If they served "lobster thermidor" no damn wonder that there was a riot!
The proper way to cook lobster is boiled in sea water and it is best eaten right out of the shell, washed down with cold beer. Some non purists may dip it in melted butter but to mix that lobster with some thermidor shit is criminal and any resulting riot should be at the liability of the chef!
I know nothing of Danny and Rebecca Guthrie, but if they approved the menue the guests have every right to be pissed off!