One of the repeated things here and on RGB is that people are surprised that many players do things they are not forced to do. I do not know whether it is geographical, but in Great Britain players often do so: if, for example, they have forgotten their system, and are reminded by partner's explanation, they often tell the opponents they have made the wrong bid to their own detriment. One opponent did this against me a couple of days ago. It is like pointing out your own revokes which is not a requirement but many players do.
So there is no need for surprise if a person does it. Also, as Robin points out, they may do it for legal or quasi-legal reasons. By quasi-legal I mean when they think they ought to say something but they have misunderstood the legalities.
Another thing that surprises me is that many people have very clear ideas whether players have agreements or not. Well, lots of player do not hav clear ideas.

It is certainly not uncommon for me when playing with some of my partners to guess what our agreement is. It does not mean we do not have one, it is that I do not know whether w have. It happens, especially at club level.
The other thing that interests me is that E/W called foul when they realised they might have got a better score. Well, if the correct explanation is natural or undiscussed they were not misinformed so no reason to adjust. But suppose the correct explanation is transfer?
East could have had his pass back if he called the TD. But are you seriously suggesting he would do anything but pass? No way!
But E/W might have a case:
West might have doubled 2
♥. He might play - as I do - that a double of a natural 2
♥ s takeout, but of an artificial one is penalties. So E/W do have a case if there was MI.