I haven't had "your fish got away" as much as my line would simply drop. It might've said something too quickly for me to catch, but I have had it to where my line would just *bamf* and suddenly I wasn't fishing anymore. I assume it is lag, because it's usually what was occurring at the time. Almost too slow to catch my bobber, for example.
Though, it is also possible you "caught" an item, that is a 510. Because there is the Horde pole that gives +25, plus the lager. Test the area again with a +5 fishing set of gloves. I do know Kayceen has the ench.