Vidding discussion

What says the netiquette about this? If I make all reasonable effort to contact the vidder but get no response, can I still show it at a con. Or would that considered bad manners? So far nobody I've asked said no and has indeed been very happy about it, so it feels like a waste of a brilliant vid not to show it on the slim chance that the vidder would not like it to be shown. At it's still up on the LJ journal on vimeo, so it's in the public domain anyway.