Well, mine once blew off from a backfire and took the fuel line with it...fire started. Put fire out, reassembled and rode home.
At the risk of stealing Scottie's reply "you're small inferno was the Mikarb killing itself"!! He was right. To me, that's "what it means when the carb pops off"
Do yourself a favor and go with the flatslide Mikuni, Ace Canister and Ace alloy manifold. You can do this all for under $300. Oh, and Ace's canister come with the mounting bracket that supports the whole carb arrangement. Not to mention the 25% HP increase. It'll be your best money spent on a mod...right after shedding the OEM silencer for a free-flow.