Stainless steel in contact with molten plastics - useable after cleaning?

(Context:) Years ago, I borrowed a stainless steel pot to an acquaintance. When they returned it, they apologised and said they had accidentally molten significant parts of a plastic ladle in it. As far as I know, they used a common home gas cooker. I don’t know what happened exactly, but the pot seemed to have been thoroughly cleaned as no plastic residue was visible in the pot. I have always assumed that steel is useable after cleaning even when plastic has molten on it, and that the cleaning process has been succesful when no residue can be spotted on the steel. Today I pulled out the same pot out of the cabinet and started wondering whether this is really true.

So my question is: After contact with molten plastics (at usual temps of a home cooker) and removal of any visible residue, is there any reason not to put stainless steel cookware back onto the stove?