Brentford head coach Dean Smith felt that QPR's dramatic late equaliser shouldn't have counted after Romaine Sawyers was pinged for a foul.
Rangers were trailing to two Lasse Vibe goals and seemingly heading for a fourth straight defeat with the 90 minutes up.
But in front of a half-empty Loftus Road substitute Matt Smith halved the deficit three minutes into added time.
And a minute later a remarkable turnaround was complete as Luke Freeman bundled in an equaliser to snatch a 2-2 draw.
Smith felt his midfielder Ollie Watkins was fouled in the build-up to Rangers' first goal, and that Jake Bidwell's free-kick which set up the second should not have been awarded.
"It was extraordinary," he said. "Romaine Sawyers pulled out of a tackle but a free-kick was given and they scored another.
"I'm puzzled to be honest. I will speak the the officials. I'm very disappointed. The referee has got to do better.
"But we got involved in a scrappy game. We stopped playing football and forgot what we were about."