What time would have been appropriate to discuss your sexual status with a person you haven't met yet?
From personal experience, I could usually tell from the jump whether a chick is a virgin or not because I always ask the question from the beginning, "when was your last relationship and what happened." A tell tale sign is that they don't have really any dating or real relationship experience because of being a virgin, so I'm slick with it and ask politely and more times than not you'll get the answer.
The majority of chicks will answer the question if you ask and I'm guessing in this example he didn't ask or pick up the cue from the getting to know each other phase.
I actually had this exact situation happen a couple of weeks ago where a chick said that she had no real relationship experience and turns out she had only slept with only 1 guy just a few months ago. I tossed her to the bushes not for that reason, but more so the fact that she was terrible at conversation and her vibe was rather immature like to be a 35 year old woman.