yep, his may be papered but they may look like pits as the breeds are very simular. to tell you the truth most council rangers see amstaffs as pitbulls that is why they are not allowed to breed asses the dog and are only allowed to issue the owner with a notice to get their dog assessed by a profetional.
pits originated from cross breeding amstaffs. you only need to have a dog caged if it is a restricted breed or if the dog is demed dangerous. and before a council can lable a dog as dangerous they must get a qualified person to do a temperment test. it sounds like he does own amstaffs but they have been demed dangerous because they are to agressive ect thats why he can still breed them but must have them caged.
both my amstaffs are great loyal dogs, shayton barks and can look scarey but he will not bite he just tries to scare people away and charlott is an absolute baby who does not even bark. garanteed if any of my dogs were to ever bite wit would be my chihuahua before my amstaffs ever would.
Just wanted to point out that Pitbulls originated from crossing Bulldogs with Terriers, bred for fighting.
Interesting read about the full history of the Pitbull Pit Bull Breed History -- Pitbull