I read nothing but good intent in your comment, so this is not me throwing stones, but one comment I would make is that I think using the term "prior art" - coming as it does from patent law - carries an overtone of "I am implying that you might have ripped off someone else's idea".

It's clear that this is not what you intended, but I think from the response from the creator, that was the tone that you accidentally conveyed.

Just a thought for the future :-).