Brentford manager Mark Warburton felt Jeff Hendrick should have been sent off for his crunching tackle on Tommy Smith before setting up Darren Bent's late equaliser.
The Bees were leading 1-0 thanks to Alex Pritchard's fantastic strike but, in the dying moments the midfielder went in two-footed on the Bees forward by the corner flag.
Referee Graham Scott only booked the Rams midfielder and the visitors were made to rue that decision as Hendrick's shot found it's way to Bent to fire home a stoppage time equaliser.
He said: “I thought the tackle in the corner was a red card and the guy is involved in the equalising goal.
“From the replay I've seen that's a shocking challenge and the guy should go.”
Brentford should have been out of sight but Jonathan Douglas had a shot cleared off the line and Andre Gray missed two golden chances to seal the victory.
Warburton added: “With the chances we had, we should have been two or three clear. We played good football.
“Our full backs were key and I thought we played very very well. It's not about a striker (Gray) but it's about what we do as a team.
“Before you criticise, make sure you're not perfect. The passion on the pitch is out there. They're winners.”
Warburton revealed that the Brentford squad had heated discussions after the final whistle as frustration boiled over.
He added: “We want them to talk and take ownership. The group is outstanding and it's a really good squad of players.
“We have four games to go and we will go about our business and see where we are.”