I use a bottling bucket with a spigot. I had never reeally considered the spigot as a potential infection source until I tasted my ESB a couple of months ago.
The ESB was the first batch that I had bottled after converting my bottling bucket into a part time Zapap mash tun (and part time bottling bucket). The batch got infected, although it did not apear to be infected in the secondary. Since then I have been careful to disassemble it after each brewing session, and have had no more infections.
BTW the beer was drinkable, just cloudy, and the bottles gushed a bit.
- magno