Not acceptable IC perhaps.
Lots of things are unacceptable but happen anyway. Forgetting an anniversary to talking loudly on a cellphone while at a teller to dating someone in high school that your friends told you was bad news and you parents didnt approve.
Some decisions will lead to consequences depending on getting caught, called out etc.
Others can be hidden or worked around.
Whats important is how you react to it , not what should be done or isnt allowed.
And in this case, the most you could do is chastise them and have an ic argument/debate.
Which you did.
As far as I can tell you rped your side as you saw was proper and the other side rped as they saw fit.
If nothing else, it added to the rp environment that these new padawans need more direction. Perhaps a long term decision to train your own padawan more stictly could come out of this , with warnings of stay away from those naughty ones.