No i think it's justified. Throwing an egg at someone because you don't like how they are doing their job is the work of a simpleton
Chinning someone who has thrown fresh produce at you is a measured and justified reaction. Plus it's not the same as flinging things about like monkeys throwing their faeces, it's the act of controlled well directed retribution.
An act of controlled and well directed retribution from an Arsenal fan at what is going on, is not to pay for season tickets, matchday tickets or merchandise