That's definitely a good point, but my personal reaction in that case would be to not make that claim. Such claims feel insincere to me and I'd rather hear "an excellent tool for creating animations and exporting them to SVG and SMIL" or something similar. I'm not saying I'm a marketing guru by any means, though. Just trying to give my honest feedback as one of the target audience.

Since Universe is Infinite, it is scientifically impossible to prove non-existence of something. Still people tend to claim of being first at something. Americans claim they are first humans walked on the Moon. Is it provable? Did they monitor the Moon all the time it's exists? May be there was another civilization of humans which waked all over the Moon centures ago? Did Columbus discovered America? - there were people living on the land! etc. It is all relative, sure.