Stephen Dobbie had given Palace the lead but Jordan Rhodes skilfully put Rovers level later on in the game.
But Holloway was more bothered about the treatment that striker Glenn Murray got and felt that he should have been awarded a penalty.
Holloway told reporters: "He could have scored today. Without being shoved 10 yards. Am I exaggerating or not? Without being shoved completely as you're going to head it, onto your back, he would have took the penalty.
"Without them cheating at that point, because that's what it is isn't it? You can't defend properly so you shove somebody over and the ref didn't see it, what more do you want him to do?"