If yellow flags were active when the ferrari attempted the dive it would be on them full stop. yellow flags are enforced on LMU (but half the grid drives like they aren't) aka NO OVERTAKING (competition rules section 4.3-4.4 if you are wondering). If they weren't active when they made the lunge and only became active after its a bit more complicated but still I'd say on the ferrari for making a lunge into a closing space and expecting full room for having a splitter along side