A 3-3 draw looked virtually impossible when the Rams hit the Millers for a three-goal 10-minute salvo after the break and their bench were exuberant in their celebrations on the touchline, with boss Darren Wassall in particular enjoying his side's goal burst and interacting with home fans.
However, Wassall cut a different figure at full-time after his side capitulated in the final 10 minutes and allowed Rotherham to wipe out their three-goal lead.
They wily Warnock noticed Derby's antics earlier in the half and was happy to rub it in after the game.
"They’ll be going home thinking they have lost and quite rightly, you shouldn’t concede three goals should you," Warnock said.
"I saw the bench celebrating quite a lot at 3-0, I didn’t see them celebrating at 3-3, I was quite pleased about that."
Wassall, in his first managerial role, could be forgiven for thinking that his side had the three points wrapped up and condemned the capitulation.
"For 82 minutes I thought that was the best we have played all season," he said.