Weddingbee boards

We're buying our own alcohol and bringing it to the venue. It will be served by a licenced bartender, but my dad was wondering if we need to get some extra insurance to cover us in case somebody drinks at our party, leaves, gets in a crash, and sues (worst case scenario, I know). We're providing a shuttle bus to minimize the chances of this (and there will be a police officer on the premises to handle anybody who gets out of control, which is unlikely), but I wasn't sure if the venue's insurance would cover this, or the bartenders', or our homeowners, or what.

Has anybody else thought about this? 

Ask your bartender first.  I hired a bartender for work last September and the main reason we did so was because the bartender was licensed and insured.