He was on the radio as some parts of the race moved right. Lots of riders hadn't reacted yet either. I've got no particular skin in this game bit it seems pretty obvious that the Uno-X rider was at fault - he overtook on the left, then chopped across too quickly. Like, I still think it was a complete accident and these things happen, but I don't really see how this could be viewed as Pog's fault.
I don't think being on the radio makes it Pogacar's fault, it was just badly timed.
I also think that you can see Pogacar straightening slightly just before they touch wheels – again, doesn't make it Pogacar's fault, but I think the prior direction of travel lulled THJ into angling in like that (it's a bit clearer from the moto shot, but you can see it from above, too; he drifts to the right about 1m when Lipowitz moves then straightens).
Genuinely, I think it was a racing incident, I don't really think either are particularly at fault – THJ went in too aggressively then the little straightening made the crash inevitable.