Jerry.....
One could go on and on about breaches of courtesy while fly fishing.
One day, while fishing striped bass at Montauk with Peter Minnick in a flats skiff, the bass were blitzing the beach. Surf casters were chucking hardware out to kingdom come, so we stayed out of their range.....not only out of courtesy, but with survival in mind. (If you get close, they take aim at you .)
I hooked a good striper which ran toward the beach. One of the surf casters hooked my line and landed my fish. He started to cut my fly line, when another fisherman admonished him not to do that........so he unhooked the fish, kept it, and allowed me to retrieve my line. That was a special form of courtesy.
Kudos to the chap who had mercy on my fly line !!
Gordy