I don't see anyting wrong with it. Especialy cuz that story would have sounded off to me to begin with. I did one on Karma's dad before I gave him his contact info, when I found him. I didn't want Karma trying to start a relationship with him without knowing his history. I don't see anything different with a romantic relationship.
And you're right, if he'll lie about that, what else is he going to lie about. Like SN said, what's the difference between that and an STD test. Someone can say they are clean, but how do you know for sure.
It's sad that that is how it has come to be, but better safe than sadly surprised.