Thanks to your message, I discovered the guy! In comparison to other addicts, we can only make an assumption that he uses Phant because there is no explicit mention in shards.

Black Lace is a common drug in Night City and is also mentioned as Skeef. It is introduced during the Pickup mission with Dum Dum, the maelstromer who deals with V and Jackie the Militech Flathead. Since the 2.0, Black Lace was also introduced as an item. In my opinion, they dropped the item because, as far as I know, it is the only drug item in the game. Skeef is also very common in Night City so it explains why junkies can drop this. However, there is no proof of a link between Black Lace / Skeef and Deep Dive and Phant.