There's only a couple of kilometres of Iraqi territory separating Iran from Kuwait. If they got hit in Iran it might be plausible they might have made it into Kuwaiti airspace before crashingWould Iranian AD even be able to reach into Kuwaiti airspace? Given that the F-15 lost its vertical stabilisers, it wouldn't have been able to travel very far before it fell into a flat spin. I am leaning much more to friendly fire/Kuwaiti AD being trigger happy, probably because they're paranoid of all the missile and drone strikes going about.
Edit: after seeing the video of the hit, looks like the F-15 didn't even bother to manoeuvre so possibly an IR/passive missile?

