Pearson accused Michael Chopra of kicking out at Wes Morgan and then Daryl Murphy of elbowing the City skipper in the build-up to David McGoldrick's late winner.
"We weren't at our best but still had enough chances to get something out of the game, although other off-the-ball incidents contributed to the result," said Pearson.
"All you have to do is take a look at them. I'm not a sour grapes person.
"Mick (McCarthy) is doing a really good job here and I don't want it to turn into me looking for excuses, but unfortunately a couple of very unsavoury incidents possibly contributed to what happened.
"He (Morgan) got booked for complaining about somebody elbowing him in the face. Everyone could see that. Chopra kicked him off the ball just prior to that.
"All in all it was a bit of a scrappy game but we had chances and didn't take then. We didn't deserve to lose but credit to Ipswich."
Leicester now sit off the pace in the automatic promotion race - eight points behind second-placed Hull City.