"It should not be a penalty. It was a perfectly good challenge. He got the ball and the referee is in a very good position to see it," Sky Sports News quotes Pearson as saying.
"If he cannot get that right it is laughable. It is about time these people became accountable.
"There is a team of four people out there and we need to utilise the four of them. I have seen the incident on television again and basically it is a good challenge from Whitbread."
Pearson went on to say that his side played well enough to have won the game, and called for fourth officials to be give a "worthwhile job" to prevent errors occurring.
"I think the players have done well today and played pretty well. We did enough to win the game but unfortunately we have had that opportunity taken away from us by other people who have not done their jobs properly," he added.
"We should have had three points but we haven't. Forest getting the second equaliser took the impetus out of the game. I don't think we have had a fair deal today.
"I am not anti-officials, but they need as much help as they can get. So give the fourth official a worthwhile job or don't bother with them."
The result leaves Leicester in fifth place in the Championship table, four points ahead of Forest in 11th.