Sounds like it was a bit of an extreme action for a couple that was having an argument. Things happen, if there was no violence or anyone on the bus endangered then the "kicking off" was way out of line.
Like others, I'm sure they are curious as to the publicly unmentionable events that occurred, are you able to send a private message of what may have transpired? It's all for curiosity, nothing more nothing less. My husband and I have been in similar situations, and things were handled differently.
All I can say is WOW.