Without the photograph, I would say that the cause is likely to have been one pint of Thwaites too many at the "Craven Heifer" from just up the road. With the photograph I would say one pint of Thwaites too many at the.......
Strange place is Ribblesdale!
W.
PS. There used to be a WW2 rifle range about a mile SE of where the photograph was taken although I doubt that the two are connected.