It’s generally not hard to read a politician. You instinctively know when they are being sincere and when they are bullshitting. When push comes to shove, they just aren’t as smart as they would like us to believe they are. They are inherently bad actors. The only people they ever fool are themselves. You know the form. We could all tell when Boris Johnson was lying. It was whenever his lips moved.

But there are the odd moments when they are impossible to read. When no one can really be sure what is going on. Are they playing a sophisticated triple bluff? Or have they entered a parallel universe where they are so detached from reality that even they have no idea what they are doing? Wednesday’s prime minister’s questions was a case in point. One for the connoisseur of madness.

It had seemed a fair bet that Rishi Sunak would seek to embarrass Keir Starmer over the Taylor Swift freebies. After all, this hasn’t been Labour’s finest hour. Allowing a virtual non-story to run for the best part of a week.

We’ve now reached the point where the Tory press – some of whom were at the Wembley gig on a freebie themselves – have concluded that the prime minister masterminded the Vienna bomb threat so he could organise blue-light travel in exchange for 10 minutes face time with Taylor. “I love your work.” “Who are you, again?” Awks. Obviously I would have told her to take the Jubilee line on the tube like everyone else. Or take the bus. Be good for her to see how normal people live.

Quite why it has taken Labour more than a week to get its story on the Taylor Swift gig straight is anyone’s guess. And now we’ll never know, as the leader of the opposition didn’t think to ask. There again, I seem to be about the only person in Westminster who wasn’t offered a freebie – or maybe I was, and just deleted the email as I really wasn’t that bothered. Three hours is a long time to stand up and watch a dot move about on stage.

Nor did Rish! seek to have a go at Labour over national insurance. Starmer’s recent protestations, that when he had insisted that the rates of NI would remain unchanged he hadn’t intended anyone to actually believe him, haven’t been his finest hour. We’re now expected to believe that we all knew Labour was only referring to personal contributions to NI and that it was obvious he planned to increase employers’ contributions. Which invariably get passed on to employees.

Silly, silly us for taking Keir at his word. It reminded me of the time I pointed out to a builder that the kitchen floor he had laid was not level. “Ah,” he said. “You never told me that you wanted it to be DEAD level.” That was a lesson that cost me another several hundred quid.

Quite why Starmer can’t come clean on tax is mystifying. Just reverse the cuts to NI that the Tories made as a desperate election bribe. Tell us they were unaffordable. We would all accept that. It’s no less than the truth. But third-rate deception is all we got.

But instead of addressing any of that, what we got were six questions on China. WTF?? No one could quite work out what was going on. Tory backbenchers looked pained. A rare feelgood opportunity had gone begging. Labour MPs couldn’t believe their luck. In a way it was quite reassuring to see that Sunak had a serious side. After all, he had never shown much interest in international relations when he was prime minister.

More likely, though, Rish! has entirely disengaged. Not just as leader of the opposition but from politics completely. Can’t even bring himself to do a couple of hours preparation for what would be his penultimate PMQs. He’s already checked out. Not long to wait until he can put his feet up for good on a California beach. A chance to enjoy all that money that someone else has earned for him. Nice work if you can get it.

Keir just looked more startled than usual. He would have to wing this one as no one had briefed him on anything to do with China. Just remember to say that China was bad without promising to do anything that might annoy the Chinese. That’s about the full extent of our diplomacy with President Xi.

“Chinese activity near Taiwan is not conducive to peace and stability,” Starmer said. No shit. This was international relations for dummies. Would he condemn the Chinese for clamping down on democracy in Hong Kong? Mmm. Yes, on balance he thought he just might.

We all kept on waiting. Waiting for the killer question. The one that would make sense of Sunak’s sudden interest in China. But it never came. There was even less to see than met the eye.

Why had the government cancelled the registration scheme for foreign spies? “We haven’t,” said Keir tersely. He just hadn’t implemented the one that the Tories had also failed to implement. Both Labour and the Conservatives have come to the conclusion that the best move in international relations is often to do nothing.

And that was pretty much that. Keir didn’t want to waste his pre-cooked signoff so he just shoe-horned it in regardless. Nothing to do with China or anything that Sunak had asked. Just a tirade about every Tory failure of the past 14 years. Sad face from Rish!. He didn’t know what he had done to cop all that abuse. Come the end, Starmer could only keep saying how shocked he was by everything, while the rest of us wondered what had just taken place. Nothing, probably.

So the Tory party retreated yet again into irrelevance for another week. They are finding opposition tougher than expected. No one is even really that bothered who becomes the next leader of the opposition. Mainly because with the choice narrowed down to KemiKaze and Honest Bob they are screwed whatever they do.

Though Kemi is still the happier of the two. And not just because Michael Fabricant publicly endorsed Jenrick. But also because Honest Bob delivered yet another dreary speech to a crowd of no one. Every time he opens his mouth another of his dreams dies. Today he wasn’t even aware that Thomas Tuchel had been chosen as the next England manager. His horror at a German being in charge momentarily silenced him. For you, Bob, the war is over.

• Taking the Lead by John Crace is published by Little, Brown (£18.99). To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.

• A year in Westminster: John Crace, Marina Hyde and Pippa Crerar. On Tuesday 3 December, join Crace, Hyde and Crerar as they look back at a political year like no other, live at the Barbican in London and livestreamed globally. Book tickets here or at guardian.live.