It's likely it won't be locked due to a single event of vandalism. I don't know if you recall, but a user unleashed vandalism recently on Aurora's guildpage to the point he had moved it several times, replaced all the content, changed the name, and well... trashed it completely. That guild page is still open to public edits.

Your page won't be locked, and to be honest, I've seen worse vandalism on Armor/Weapon pages that goes unnoticed. Just revert the edit, and if it bugs you so much, let the user know on their talk page. If they continue to vandalize your page (or others) the mighty Equinox is all-seeing and will notice, and will probably gladly drop the banhammer over that derp's head ;)