And Villa striker Carew insists he has seen players sent off for less serious challenges after team-mate Milner was caught on the knee by Blues skipper Terry's second-half lunge at Wembley on Saturday.
The England defender received a yellow card from referee Howard Webb to add to Villa's anger after he had rejected early claims for a penalty when John Obi Mikel fouled Gabriel Agbonlahor.
Carew said: "I saw the challenge from close range and Terry could have sent his (Milner's) lower leg up into the stands.
"I've seen people get red cards for less. That was a really dangerous tackle.
"There are a lot of tackles that can break legs which are not really that dangerous.
"But that one was very dangerous because he launched in with straight legs. It would have broken it."
Carew and Villa's frustration was compounded after they felt Manchester United defender Nemanja Vidic should have been sent off in the Carling Cup final after pulling back Agbonlahor inside the penalty area.
The Norway international said: "It seems like we have the important decisions against us in those games and it is really sad. It makes things difficult for us. First United and then Chelsea.
"We are working hard and creating good situations on the pitch through good play, good movement and hard work.
"Then, when we don't get the right decisions, it is going to be very difficult over 90 minutes to win these type of games.
"We put pressure on them, create situations and then, when it is a penalty kick, we have to get the penalty as was the case against United.
"It will be very difficult to defeat United in a final and Chelsea in a semi-final without getting what we deserve to achieve.
"In the Carling Cup final, it was a clear red card, for some reason it wasn't, and on this occasion it was a clear penalty and the game would have been different if we had got it.
"It is all about these small margins against the big teams. If you are going to have any chances in these games, we need the right decisions as well."
Carew insists Villa can be proud of their efforts this season despite missing out on silverware.
But he admits Villa may have to win all of their remaining games to stay in contention for a Champions League spot.
He said: "I think we've had a really positive season. We've been in one final and one semi-final and we are still fighting for fourth place so we should be really happy with our season.
"We should be proud of what we've done but you are always hoping you are going to make it all of the way and unfortunately we haven't.
"But in all the seasons I've been here, we've improved every season. Now we have to win most of, maybe all of, the remaining games to have a chance of coming fourth."