The comment has already been made, and I don't approve of the use of methods that injure any creature, but I would add that the fish that escapes with a hook in, or ripped out of, it's mouth is severely injured too, and that's legal catch.
You are quite right Bogflogger, guddling for trout is illegal in the UK; despite the fact that it causes no injury unless it is actually caught for dinner.
I'm sorry that this thread is offensive to you, personally I think it's been taken quite nicely off topic to discuss non mangle, strangle, dangle or tangle methods of fishing, that theoretically, one could apply in the Falkland Islands.
I'd have been the first one to come down on anyone trapping any beast in an inhumane manner.
Cheers,
Toddy