He did teach zoro how to use it so I guess it's fair to assume that he has it
teaching is what Hyogoro did to Luffy into Wano… telling someone “go away and do the thing or else” isn’t teaching
the only reference we know of Mihawk training Zoro in any specific way is Zoro losing his eye. Oda’s statement was “Zoro’s train gun with mihawk was very intense” to explain why Zoro lost his eye
so as far as we can tell, the only thing Zoro gained from mihawk was partial blindness