It's not the legitimacy of the source I'm concerned about; we can't draw any firm or even somewhat mushy conclusions about what to expect from the real rollout wrt efficacy and safety, and we can't even form an opinion about what prominent gaps in knowledge might remain. Eg. did the two treatment arms differ from one another wrt subjects dropping out between doses? Who and where were the subjects? How did the subjects behave during the study wrt physical distancing? And so on. You can compare this to the situation with all the heavily promoted serological tests back in spring, where every single test seemed incredibly good, but, as soon as you examined the validation studies, they looked considerably less incredible to anyone interested in using them in the real world.
I'm cautiously optimistic that this and the other vaccine candidates will prove to be effective and safe, but I'm going to be completely agnostic wrt how effective and how safe until we can all see the detailed results and I'd like to see whether the people behind the Oxford vaccine address previously (and recently) raised concerns about vaccines using an adenovirus vector—concerns that will be especially important to address if, as seems likely right now, that particular vaccine ends up being deployed on a massive scale in parts of the world where HIV is endemic.