Sparrowhawk? Injured?

This afternoon I was in the garden and heard a flapping noise in the corner near the shed.  The cat was looking but keeping her distance.  I had a look and there was a bird - quite big but young - it was flapping half heartedly along the ground.  Geoff came and looked and said it might be a kestrel or similar.  Ben (teenager2) came and looked, took a photo and then peered at it until it flapped round the back of the shed.  It looked like it's wing and one of it's legs was broken.  We were going to 'rescue' it and take it to the vets when lo and behold it flapped off through a whole in the fence and flew off.  We think it was a baby sparrow hawk.