Referee Hilario Grajeda cautioned Union midfielder Stefani Miglioranzi for a challenge on Sainey Nyassi but produced a red card when Revs defender Cory Gibbs brought down Eduardo Coudet in a similar incident and Nicol was left fuming at the inconsistency.
"You can't give Miglioranzi a yellow card for the challenge on Nyassi and then turn around and give Cory Gibbs a red," Nicol said. "I mean, that's wrong, just wrong.
"The last three games have been huge for us, in the context of our season and two of those three games the outcome has been affected by the officials and I don't think there's any argument about that. We've had four players sent off this year. I mean, that's incredible."