Not really a stackable offence though is it? Nor is being 2nd in your league and in the running for both the title and CL. If any of us got sacked because the guvnor "didn't like us" we'd have major grounds for wrongful dismissal.
I don't know what his contract allows for, but I really can't see that there'd be a "we can sack you if we don't like you" clause in it.
Like I say, the whole circumstance is extremely weird to me.
It's not a sacking in the traditional sense tho.
If they're gonna terminate and pay off his contract then they reserve the right to do it whatever they like.

