Livingston striker Dolly Menga was "very, very lucky to stay on the pitch" against Celtic, according to Brendan Rodgers.
Menga was involved in a first-half clash with Ryan Christie as the champions were held to a 0-0 draw.
"He should have been sent off," said Celtic manager Rodgers.
"In real time, I thought he gestured with his head towards Ryan and when I saw it after the game it was actually more aggressive than I thought."
The incident took place as Livingston were defending a corner kick.
"It's not a great action by the player, so I assume the referee hasn't seen it," added Rodgers.
Livingston boss Gary Holt said he was unaware of the episode.
"No one on our staff has mentioned it," he told BBC Scotland. "It's probably nothing. These things get highlighted by the cameras playing them over and over."
Holt was full of praise for his battling side, who recovered from back-to-back league defeats to keep Celtic out.
"The lads stuck to the plan and we got a deserved point," he said.
Liam Kelly made a great late save to deny Tom Rogic and also did well to keep out two efforts from Christie, with Holt suggesting his goalkeeper merits a Scotland place.
"You just hope other people are taking note of him because I believe he should be on the fringes or in the squads for people to have a look at him and see what he's about, expose him to international football," he said.
"I think he's up there with the youngest and best goalkeepers in the league."
Broken eye socket for Ajer
Rodgers hopes to have Scott Brown, Olivier Ntcham and Leigh Griffiths back from injuries after the international break but defender Kristoffer Ajer faces a lengthy lay-off after being hurt in a clash of heads.
"He's struggling - he's broken his eye socket and he's in a lot of pain at the moment," said Rodgers.
"He will need surgery which is a shame. There was nothing in it. He's just headed down into their guy's head."
The stalemate lifted Celtic top of the Premiership for the first time this season, with Rodgers satisfied with a point after an energy-sapping Europa League win over RB Leipzig on Thursday.
"Sometimes these games, after the big show in midweek, can be flat but I think the players gave absolutely everything," he told BBC Scotland.
"The game isn't as quick on this pitch as it would be on grass. You also have to give credit to Livingston because they are very good defensively and round the box. It's a cup final for Livingston and they put bodies on the line.
"It's a good point after our long run of games. We'll take the positives out of it."