I'm sorry if this sounds harsh, but please explain to your friend that they were irresponsible in the extreme in taking out an in season bitch and as for leaving her tied up outside a shop....mad:
Not only is he risking her getting pregnant... which it would appear is likely , but the effect on male dogs is totally unfair, and can ruin the behaviour of an entire dog around a bitch... can cause a dog to follow a bitch for miles, putting the dog in danger from traffic etc... and far from this being an irresponsible dog owner that you are pleased to see get an £80 fine, it is also highly likely that it was your friends bitch may have caused this dog to have run away from it's frantic owners who are wondering why it's normally well behaved dog has taken off....