Harry Mudd and Wrongdoing are never far apart from each other, true!

However, his crimes (as stated clearly in the episode) were limited to illegally operating a space vessel. Whatever motivated the 3 women to go out seeking husbands was their own business, again explicitly supported by the episode. So, had Mudd simply followed spaceflight operating procedures he would have committed no misdemeanour whatsoever, no matter how large a "finder's fee" he eventually ended up with.
Well, until the deception about the venus drug was uncovered, anyway