Without getting in to the debate as to whether "beast" is a fantasist or not I did find three architects events (or events for architects held in November 2009.
I haven't got exact details or links currently to hand tonight but:
The Architect of the Year Awards are held in November and were held in London in 2009.
There was another annual architect/construction awards event held in Edinburgh.
There was another (perhaps less likely) architects conference held in Spain (Barcelona)
Joanna's firm would have taken tables at all events to varying degrees, because they won and/or were nominated for awards at all of them.
Even so, is it likely that a firm of more than 1200 staff would choose a relatively new employee who'd only worked for 13 months in one of their provincial offices to attend such a prestigious event? None of the nominations were for projects designed by BDP's Bristol office.