Amrutha said in her first post that,
nothing that we did cuased him to act this way it was prior to us having him that he must have had a bad time. My son is too young to even get near him like that, and none of use hurt.
" Inky is super quiet and gentle, but very friendly as well."
I really don't think he is a cat that had been mistreated or was particularly wary of men prior to coming to you. I think what you were seeing was a nervous cat that hadn't been given time to properly get used to his new home. As @sarthur2 said, it can take months for a cat to become comfortable in his new home.
There's no undoing what has been done, but I hope for Inky's sake you will make every effort to trap him and re-home him. Have you been able to contact Amrutha and let her know what happened? She might be able to help with re-trapping Inky.