It looks like the person who originally checked your signature was simply wrong, in that case. I know that on some styles, the 350px scrollbar doesn't show up which can lead to incorrect signature estimates. Honest mistake, I guess. Unfortunately, having just checked it myself, your signature is slightly over the limit so the text needs to go or the image should be made smaller or something like that.
So yeah, bottom line, mistake on our part but no harm done in the end since no infractions or anything were given. Just make the sig a bit smaller and you're all good. :]