The MRP said the clash of heads between Thomas and Reid was caused by circumstances outside the control of the player, which could not be reasonably foreseen.
The panel stated that Thomas legitimately blocked Reid because the ball was within five metres and that the North Melbourne forward did not leave the ground and initiated contact with his shoulder.
Thomas also hurt after bump
The decision is sure to confuse Collingwood coach Nathan Buckley, who made it quite clear after the game that he thought the small forward had a case to answer.
Head clash sparks war of the words
"It was off the ball and it was unprovoked. We'll see how it settles," Buckley said. "I think the AFL rules take care of that. I don't want to pre-empt anything but clearly if it is behind play and it is high you're in a bit of strife."
Meanwhile the Brisbane Lions' Pearce Hanley and Melbourne's Colin Sylvia were both charged with separate rough conduct charges. They can both accept a reprimand and 93.75 points towards his future record with an early plea.
The report against Carlton's Chris Yarran was withdrawn as the panel determined that the force used was below that required to constitute a reportable offence.
Greater Western Sydney's Tom Scully also had his report withdrawn for tripping the Sydney Swans' Rhyce Shaw. The MRP decided it was below the impact required for a reportable offence.
The report against Gold Coast's Jarred Brennan was also withdrawn after the panel determined he had made a legitimate effort to spoil the ball when making contact with the Saints' Stephen Milne.
