Not that it would necessarily be Fleur who had to play apprentice ping-pong. All of house Mercere would be up in Vulcanus' grill. I can't imagine a situation where there wouldn't be immense pressure on the rest of his covenant, and his tribunal at large if he pulled a stunt so brazen. So it's entirely possible that another Bonisagus could step in to try and repair the damage. Lucas and Fluer both could well get involved bringing it up with their compatriots - negotiating, pulling in favours, and/or getting a righteous bollocking for the mess in the first place! 
I'm actually going to start putting stuff up now, because I have an idea for the concept. Development thread!