It is likely that Google is surfacing the matches it empirically considers more relevant to you.

Possibly, but it's also a timeliness thing. This stuff has a window of opportunity: for like a week after the interview, it'll successfully game the results, but after that they may be crowded out by the reporting on the gaming itself.

If he's trying to spike negative results for just a certain period of time, it's quite an effective tactic. News cycles quickly, so even if each instance is eventually caught, it may successfully push down recent news / current events until they're no longer current, which may result in millions of people missing the reporting.

All this is possible and maybe even probable but not knowing how Google determines relevancy, makes it impossible to reason about.

I've just realised that another example of this was his momentary diversion on building a bridge between Northern Ireland and Scotland. This reeks of an attempt to divert attention from his failed garden bridge project as London Major. Googling "boris johnson bridge" is filled with articles about he former for me at least.

The thing is, it doesn't have to be completely successful for it to be worth his while doing. It probably serves multiple purposes, like changing the current news cycle.

This is insane. He's been a politician for many years. What could he possibly say that doesn't have any nouns in common with some other issue? Busses, models, bridges, what else is Johnson now banned from life for mentioning?

I'm not a big believer in conspiracy theories and I'm the first to admit that this could be entirely coincidental.

However, my gut feeling is that that some of these statements were so unusually phrased or just plain strange that I'm leaning more towards this being a deliberate effort to obscure some unfavourable stories.