trapped Magpie

A slightly bizarre start to my school day. (It's amazing how often I get called to 'bird incidents' - do other ringers experience this?) "Mr Leonard! Mr Leonard! Come quickly! There's a baby bird trapped on the fence!"
What?
Well I went to investigate, and sure enough, a young Magpie had slipped from the top of a narrow picket fence and found itself trapped with it's head between two slats - the fence had an almost faultless ringers' grip. Anyway, apart from slight grazing on its head, it was fine and released after a brief lecture to the assembled crowds...
Pete