Someone piss in your wheaties this morning? Some of you guys just love to belittle others at every turn... It's OK to not be a prick.
There are other parts that could be attributable, but typically the simple solution is it. It's also easy to rule out, and a spare relay is good insurance to have in the glove box.
No need to wait for it to happen again, either -- check for continuity between the two main studs on the relay. With the battery still disconnected. Requires a multi meter and not a test light, but will confirm or rule out whether it's welded together internally. This is a regular occurrence in the motorcycle world and typically caused by low resting voltage brought on by periodic use or marginal charging systems.