I would hold back armchair quarterbacking this CA. Did the FBO even have stairs? If so, were they available or in use?
And to echo others, blowing the slides is a very bad idea unless there was greater danger inside the plane. You will injure people when you send them down the slides. Especially considering that one of the medical concerns was a paraplegic.
B6 certainly should've done a better job than 7 hours, and may well get fined, but as for the crew, sometimes you're just stuck