Hmm, looks like you think the same as me.
I gave him the benefit of the doubt because I know, from visiting this particular fishery regularly, that he's not used to running it hands-on (I discovered he's one of the estate owners), and because he's not an angler himself, he's maybe not aware he was doing anything wrong.
But I should probably have said something - by not doing, he won't know he was out of order and could easily keep doing the same kind of annoying thing.
Lesson learnt - I'll not let this kind of thing go without comment if it happens again.
The fishery could lose business because of this sort of behaviour, especially if it happens to someone more outspoken than me