BRfares is wrong.
The correct version of the restriction code is at NRE :
http://www.nationalrail.co.uk/times_fares/ticket_types/64160.aspx
As can be seen, the ticket is valid from Waterloo at and after 09:00, subject to certain easements.
For what it is worth, I believe that, where restrictions reference a specific station, and both ticket and journey start from that station, generally speaking, those restrictions and those restrictions only would apply, unless the wording of the restriction code expressly states to the contrary. For example, a passenger may board a weekday 'evening peak' train at Milton Keynes with a '9I' Off-Peak ticket, notwithstanding that the same train would be barred for passengers wishing to board at London Euston or Watford Junction. Indeed, imposing evening peak restrictions from the origin station
of the train on regulated SVRs for journeys commencing outside of 'London stations' may violate fares regulation, albeit that few, if any SVRs with restriction code US would qualify, since few SVRs, as distinct from Network Awaybreaks, existed in 2002 for journeys wholly in the Network Southeast region.
It seems to me that, even were the BRfares version correct, the plain intent would be for journeys from Vauxhall to be permitted at or after 09:05, and that in any case a passenger ought to be entitled to benefit from any ambiguity.