I hope the landlord is successful in suing for unfair dismissal.
Some pub owners/landlords do behave like dictators. There is a famous pub in Edinburgh that used to be very busy. The new owner has a sign outside the door saying "no gypsies or students" It is always very quiet now.

I was once told to leave a bar because I had long hair. Of course the landlord didn't say that. He said it was because I wasn't wearing a tie but there were several short haired guys in the bar not wearing ties.
My mates and I ignored him for a bit then he suggested we all go down to the bottom of the garden to sort it out like men. He was a podgy middle aged man we were four super fit guys in our twenties. He was obviously suffering from early onset dementia so we took pity on him and left his pub.