Arsenal's first goal is 100% a goal, no case for the Rags to be moaning, nor is there any 'injustice'. You don't straight up go down hoping for the ref to bail you out when play is so dangerously close.
If the ref had chalk that goal off, that would be real injustice. Would've set a terrible precedent where keepers can just go down pretending to be injured, and every goal that goes in after will have the potential to be cancelled. Like what's the point of having defenders/keepers then? Just stick someone there and have them catch a cramp each time the oppositions shoot.
Just seems to me like De Gea is used to the ref being on their side all the time, and thinking this time will be the same, shite mentality. Makes it even more hilarious if he learns Fred's the one who stamped him.
Overall, both teams were shite. Rags overall maybe just a tad inch better, if I'm being fair, but still shite. Far from a classic, looked like two bottom-half sides trying to play 'fancy football'.