Williams was sent off for a studs-up tackle on Roar defender Ivan Franjic in last weekend's 3-2 Heart win at AAMI Park - a challenge the striker admits was clumsy, probably deserved some sort of action, but was not malicious.
However Williams and Heart coaching staff were upset by Roar goalkeeper Michael Theo's late lunge which collected the striker as he scored the team's opening goal.
They were surprised that challenge, which left Williams on the ground for several minutes afterwards, wasn't penalised in some way during the game or by the match review panel.
Williams believes if his tackle deserved a send-off and ban, so did Theo's.
"There was no ball taken at all. His feet were a lot higher than mine. I'm not being petty about it, but the refs have to be consistent," said Williams, who had never been sent off in the A-League before the weekend.
"It was a clear tackle without the ball on myself - doesn't matter if it's a goalkeeper or an outfield player. If that's not a red, I don't see that mine should be a red."
Williams received an automatic one-match ban for his send-off, and hasn't trained this week as he receives physiotherapy on a foot ligament injury which could even sideline him beyond his suspension period.
Williams did play on with the injury until his send-off.
"I'm feeling it now and, even if I wasn't suspended, I'm not sure if I'd play the next game because of how my foot's going," he said.
"Mine was a bit of a clumsy challenge, but (the decision) is definitely not consistent with the challenge on me when I scored the goal."
Williams' comments echo those of Heart coach John Aloisi post-match about refereeing.
Aloisi believed referee Alan Milliner and his officials lost control of the game and lacked consistency in their decision-making which confused both sets of players.
The match featured a clearly offside goal given to the Heart among several contentious decisions.