Beholder in a 3rd-level party - what's the worst that could happen?

[Aharon]

Using a simple interpretation of the 90º arc separation for the eye rays the beholder could fire 3, move and change his facing, fire another 3, move again and fire 3 more... plus the last ray somewhere else in there because he's bound to find an angle to use it at.

I held this interpretation in the past. Cog convinced me it is wrong in this discussion: http://www.giantitp.com/forums/showt...(Sanity-Check)