Leicester centre Anthony Allen was "dazed but okay" after being carried off during their 17-12 Aviva Premiership win over at Welford Road.
Allen, 26, was left unconscious for several minutes after a high tackle from Matt Banahan, one of three players to be sent off by referee Tim Wigglesworth in five astonishing minutes.
Bath flanker Francois Louw was first go on 60 minutes for use of the elbow, and Banahan followed after the tackle on Allen, as did Leicester flanker Brett Deacon for retaliation.
Bath also saw No 8 Simon Taylor and fly-half Stephen Donald sin-binned in the 50th and 67th minutes respectively, and their indiscipline helped Leicester hit back from 12-6 down at the end of the third quarter to win 17-12.
Leicester boss Richard Cockerill said: "Anthony is sat up in the changing room, he is dazed but he will be okay."
But Cockerill had some sympathy for all three players who were sent off.
"Banahan is a big man, he's not a dirty player. He has gone in and hit him high," he said.
"The laws are a bit mad. If Louw has dropped an elbow on someone is it a red? Probably not. It might be a yellow, but that's the world we live in.
"Banahan hits a bloke and knocks him unconscious, but it looks a lot worse than it is. Brett Deacon retaliates and he is off.
"If you go back to the 1990s when this side was very aggressive we would have three blokes a side. I don't necessarily agree with how it's refereed but that's the way it is."
Bath head coach Toby Booth said the game was "one of the most surreal experiences" of his career.
"I am a bit shell-shocked. When you come to Welford Road you have to be extremely competitive and we spoke about that a lot this week.
"Self-control is part of a professional player's make-up. Some of the issues we saw out there were self-control issues, others were consistency issues.
"I am not going to stand here and say it should not have been (red card). I did not see Francois' incident, it was off camera.
"Allen ducked into a tackle from Banners and he has caught him high. We are bitterly disappointed because we thought we had an opportunity today."