I get what you were going for here, but I think to some it might have come across as unimportant pedantry. Perhaps phrasing your initial comment as "Fun fact:

I get what you were going for here, but I think to some it might have come across as unimportant pedantry. Perhaps phrasing your initial comment as "Fun fact: the call sign..." would have been better received? I dunno, people are fickle sometimes.