Hirst was already on a (soft) booking when he decided to shoot, long after the whistle had blown for offside, when the score was 0-0 just after the half hour mark.
The Scottish international went on to score the second goal of the game as the Blues beat the Championship leaders to move up to fourth.
Asked whether he felt Hirst should have still been on the pitch, Lampard replied: “No, he shouldn’t, he shouldn’t.
“And I don’t love yellows for kicking the ball away, but clearly if Josh Eccles deserves one (for doing the same earlier in the game), then Hirst unfortunately deserves one.
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“This is nothing personal on Hirst, but it’s the rules. And if anyone’s going to speak about the timing of it, it was whistle, stop a little bit, look, shoot wide, just like Josh did. So unfortunately for us, that went against us today.”
Reflecting on his side’s display, Lampard said: “In the first half we were the strong team for me and you could feel the stadium feeling it. We were very clean on winning seconds, our press was spot on and they struggled to play through us. I think that brought some angst to the stadium.
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“When the goal comes it’s scrappy – crosses, crosses, drops to them – and they score. That gives a different feeling going into that half time.
“Second half, they score with a bit of a transition moment where Hirst runs through and then it’s obviously difficult.
“But I have no real unhappiness with the way the players approached it. If you said ‘which team was in the Premier League last year?’ it would be really hard to say. They’ve got a strong squad and will be right up there. It just wasn’t our day for different reasons.”