I think you should have waited.
The bit I think missed here is the hire staff probably had just finished explaining to their guests how locks work and lock etiquette and right of way.
You then go and do the exact opposite of what you acknowledged was protocol.
You can't have it both ways, hire boaters aren't going to observe etiquette on locks if it isn't returned and their very first lock sequence during their training another boater throws it out the window. You've demonstrated to them it is optional so cest la vie when it occurs in reverse and someone turns a lock in their favour against you when it was already set.
Rudeness can't be excused from the hire boat staff but, if they are trying to verbalise to you your error in order to fix the perception of their guests then I can see where this gets mis construed.
They may well have thought they was helping you with your lock wheeling.
The interaction is hard to call without being there and judging tone etc, the sequence of the locks by your account though seems clearly in their favour.