The ADC is a jerk. No matter what
Even when they buy 
when the support didn't.
Even when they only die once (because no one peeled the 
that dove the backline)
Even when the support is always backing leaving them alone in lane for too long
Even when they take 2 towers and an inhibitor by themselves.
Even when they have the most CS in the game.
The ADC is a jerk. Don't listen to anything they say ever, because they're obviously wrong to be upset at their team.