Not likely a bounty hunter’s word would be believed on something like that. Like now, bounty hunters were not much above the criminals they chased.,Besides which, a freeborn person could not be made a slave except for specific crimes. It’s more likely that the slaver outfit hired someone illegal to kill their slaves because it was illegal to shanghai someone like that and word might get out. .Even if someone got convinced somehow, why would sorcery bother them? It was commonplace in different cults. Sorcery was synonymous with drugs (back then the drugs were pot, henbane, various halucinagens, etc.).Take this example from Revelation 9:.“20 The rest of mankind, who were not killed by these plagues, did not repent of the works of their hands, so as not to worship demons, and the idols of gold and of silver and of brass and of stone and of wood, which can neither see nor hear nor walk; 21 and they did not repent of their murders nor of their sorceries nor of their immorality nor of their thefts.”.In verse 21, sorceries is the word “pharmakeon” or φαρμακειων, which is where we get pharmacy from.