In reply to Annoying Twit:
@NickD. You sick sick man, funny but not sure I would want you doing it to me
@Annoying Twit.
I use so many different styles of knots to tie in with (Fo8, bowline with double stopper, double bowline with stopper, double bowline with yosemite finish and my new best friend, the End Bend Single Bowline with yosemite finish), that I get use to spotting a knot that doesn't look right.
I would always say to the climber "is that knot ok, not seen it tied like that". It could be that it is a knot that you have just never seen before like the EBSB w/yosemite finish. But on the other hand it could be a knot that is just tied wrong. Either way its always worth a quick polite word.
I have had people that have climbed next to me using a bowline with a stopper tied 6 inches or more from their knot, when I have pointed this out they just gave me a look to say what are you saying and I dont really care anyway. But after pointing out that I use a bowline and that the stopper had to be flush with the knot, he retied his stopper. What he did after that I have no idea, but atleast I had done my bit.