Was surveillance the proper method to use in this case? Why? Please see paragraph below.

A man in San Rafael County was discovered committing workers' compensation fraud. He had been observed working while at the same time receiving disability benefits. Surveillance showed the man working at an automobile auction. The investigator interviewed the owner of the auction and found that the claimant was being paid $200 per week in cash for washing vehicles and performing other shop tasks. Surveillance video showed the man carrying 25-pound bags of pet food, loading boxes, and rummaging through a trash dumpster. Obviously, he was not hurt very badly.