I have to say, I disagree with Anne on this one.
For me, I cannot stand a Burns supper where they just randomly ready out poetry and expect to be entertained.
The suppers are in his honour and we'd do well to respect the man and his works enough that we can take 5 minutes to find out what inspired him to write the thing.

IMO, Burns suppers are not a spectator sport. I'd have pulled the heckler out of the audience, reminded him of the above facts and then asked him to perfectly recite and explain at least one Burns poem in front of everyone. If he couldn't take the heat and do a performance, as I'm guessing, then he deserves the dressing down.