The Foxes were 2-0 up at Vicarage Road thanks to goals from Matty Fryatt but a rousing comeback from the hosts meant Pearson's side were reliant on a late equaliser from substitute Dany N'Guessan to salvage a point in a 3-3 draw.
Pearson, who described the result as two points dropped, said: "It is a lesson for us and an illustration of how tough the league is.
"The first half will be up there as one of our best halves of football of the season. We were clinical. I suppose we have got something out of it.
"We will learn from it and I know we will bounce back and still be a very capable side."