Nope, or not in any widely useful way.
By definition, a distribution list will transparently route to each end user's mailbox. The only way you could possibly know the difference is if you get an OoO message from a different end-user address and are able to compare this with the recipient's original data, which you'd have to encode in the From: address.
Anyway, why wouldn't you want to subscribe them? You can't just substitute the individual email address for the list address (that's not legal) so you'd end up not being able to market to them at all. If they signed up via the distro list, that was maybe a bad move on their part, but you aren't doing anything wrong or something you can feasibly correct.