in this sellers ebay history hes bought a set of part worn, only done one track day, pirellis 190/120s. Might be another person of course, but gives a bit of credability to ownership of a bike of sorts.
I don't think the ownership is in doubt, more the actual history of the bike - do Ducati really build custom spec machines? A lot of it is old kit - SPS engine, 3 spoke wheels, gold frame, vented fairing and so on.
my guess would be an old sps that has been laying around unsold and unregistered. Only thing is, it isnt numbered?? but otherwise looks almost identical to my 98 and a mates 00 reg 916sps.