Munster sealed a dramatic late victory against Tandy's side as Dave Kilcoyne touched down to score the winning try.
Tandy was frustrated with two incidents from the game where he feels his players were unfairly tackled.
"You just want consistency. That's something we probably didn't get [against Munster]," he said.
Speaking after the defeat, which ended their 13-game unbeaten run in all competitions, he continued: "There are question marks over the officiating - definitely."
Tandy was not happy with was what he felt was an illegal no-arms challenge on Ospreys centre Ashley Beck by Francis Saili in the second half.
The Ospreys coach was also unhappy where, in the last movement of the game, referee Marius Mitrea again called for TMO Stefano Penne, to adjudicate on a suspected high tackle from Munster replacement hooker Kevin O'Byrne on scrum-half Brendon Leonard.
It was not deemed to be a high tackle, however, but Tandy believed it was similar to an incident earlier in the game when prop Rhodri Jones was penalised.
"We'd like some explanation on no-arms tackles and on the consistency of high shots - when you look at Rhodri Jones's in the first half and the ones at the back end of the game," he continued.
"You just have to question the protocols and what they are looking at and how far back. They don't want to listen to players when they are asking the question.
"But then they are missing things. I don't even know whether they looked at the no-arm tackle. That would probably be something that's frustrating for us."
"At the end of the day it is getting borderline ridiculous when you look at it. But if you are going to be consistent that's something you just want. You could argue both of them are not high tackles, the way the game has gone."
Despite being unhappy with the refereeing in the game, Tandy admits that his side should have seen the match out and keep the pressure on Munster and Leinster.
"For us, it would be easy to go down the referee route around certain aspects of the game," he said.
"But, ultimately, I think there was enough in our game today to win that match."
Ospreys head coach Steve Tandy says there are some "question marks" over the officiating in their 23-25 Pro12 defeat by Munster.