I would also add the referee played a huge part in Arsenals equaliser
He awarded Arsenal a free kick in their left back position when it was a clear slip.
There was one min to go and away team leading 2-1 and what should have been the ball rolling to a Chelsea player due to the slip became a free kick, wrongly.
Nobody will ever know, but that free kick is not given, Chelsea see out the last few seconds
Instead, crucial possetion was given to Arsenal, Chelsea never got the ball back under their control and Arsenal eventually scored
80 yards up park, yes, 30 secs or so elapsed, yes
But the whole passage of play was started by the referees wrong free kick award
Add in booking Fabregas when not even a free kick was merited and adopting positions which saw him hit by the ball twice and taking evasive action on around a dozen times to get out of the way, to the attacking teams deteriment
Wiltshire potential second yellow, ref view was blocked but thats where your AR earns his dough, a big clear shout of "dive" and we get the correct call
A FIFA AR at that? Was he leaving the call to the ref? Was it above his station?
Poor team work all round
Throw in Conte spending more time out of his tech area than in it, and, it was a poor rights work.