If my employer witnessed the majority of his workers breaking a rule but chose only 3 to fire...

If my employer witnessed the majority of his workers breaking a rule but chose only 3 to fire could we sue for retaliation?

For the past 6 months I've been working in a restaurant/bar. It was a great place to work. The money was good and my coworkers were amazing. I couldn't ask for a better group of people to spend my days/evenings with... and get paid while i did it!

The owner of the restaurant, however, is very shady and doesn't practice proper ethics in the workplace. On many different occasions I've been told (even by managers) how he steals from his employees and fires people that don't deserve it.

3 servers got fired on Wednesday for breaking a rule that 90% of the staff (including ALL managers) break on a daily basis; Drinking on the clock.

Ethically, if the owner of the restaurant wanted to fire the people who were breaking his rules he should have fired everyone--managers included. He claims that he saw the three offenders on video tape taking shots. But I KNOW the three of us have never worked together. I also know that anytime i have drank on the clock there is always a manager present-- either by my side taking the shot or pouring them for me.

When the boss man fired me (via phonecall) he said this was "job 101" and "I should've known better" but how am i supposed to know better when i'm being taught differently?

On my first day of work I went in and trained side by side with one of the managers. She was waiting tables tables that day and stayed busy for 3 solid hours. When the restaurant started to slow down she walked to the bar and came back with two shots in her hand. She handed me the shot and i asked if this was ok since we were on the clock. She said it was fine and that was just one of the perks of working at this establishment.