Do I get the awful suspicion that post 9/11 we pilots are afraid of going back into the cabin to assess the condition of the 'frame at any time we so consider necessary?
I appreciate the OP referred to an external inspection by (hopefully qualified) observers, but ultimately the operating captain is responsible etc etc.
After 3 winters operating from KEF as a base, alas I would trust NOBODY outside the aircraft to assure me of a lack of contamination!
Sad, but true, so stuff Al Quaeda and the rest, get outa yer seat and get back there at the o'wings and LOOK!
That's what we're paid to do, innit?!