I guess that Interpol had sent an arrest warrent to Thailand
You guess wrong, Interpol does not issue arrest warrants. They do issue various Notices which are advisories only.
It is not illegal for a foreigner to own that type of business but the legality of it sort of pales into insignificance in the circumstance, don't you think?
Other reports state that the arrest was a result of his alleged involvement with a 17-year old. At the location another man was arrested having been in the company of the 15-year old.
They were not intervening in any legal preceding--he had been told he could go--they (embassy) just had to arrange the plane seat.
And arranging his travel was exactly what they did. Until that was completed he could not go anywhere.