cattitude
My Sweetest Boy
JMO, but a dog isn't "restrained" if he's in a fenced yard, he is "contained" and, therefore, I think the law is, while not totally clear, focusing on the chain/collar restraints that we see all too often in and about the area. Restraint generally implies some sort of physical holding back of the actual animal and that isn't present in a containment situation. Again, JMO.
The intent of the law is to prevent a dog from being chained/tethered with no room to move around and without any attention for long periods of time. Many chained dogs do not have access to food/water and often cannot get out of their own feces or urine. The 1 inch "rule" is aimed at preventing a dog from choking and also to prevent collars from becoming embedded in the neck of a dog (in the case of a growing puppy). Many dogs that are left "tied" with little or no human interaction in many cases become agressive.
The law is fairly weak and isn't all that well written..but many laws are ambiguous. It's a start, however.