What safeguards have been removed/bypassed?
The reason that most vaccines take so long to develop is that they take time finding funding for each phase of development and testing and then at each stage of testing with people or takes time to get people to volunteer, both those add years and years to the process, something which hasn't been an issue for Covid-19.
Whilst the delivery method is new, in the case of the Oxford vaccine is been in development for a few years now and it's just programming of it to be for Covid that is new.
That post wasn't in reference to the Oxford vaccine though, that hasn't been approved. What has been approved is very much experimental.