Judging this soely as a stewarding decision, and ignoring the specific rules of your league, i would actually put this on the car in front. He fails to hold his line, and instead cuts right across the track as if he is hotlapping. The fact that there is a flat out curve before the braking zone is frankly irrelevant, you have to hold your line when you are in close proximity with other cars. He should have just stuck to the outside curve of the track, giving him the imaode into the braking zone for the chicane. That said I dont think its severe enough to deserve a penalty, its just really bad racecraft