(Disclaimer: SLF)
I wonder if Learmount considers e.g. US airports as safe and would ask the captain to ignore the hijacker.
There are articles like this:
EXCLUSIVE: Undercover DHS Tests Find Security Failures at US Airports - ABC News
(Article from mid-2015)
Assuming the article is reasonably close to the truth (and I have no reason to believe otherwise), as an SLF I'd prefer the captain to err on the side of caution, accede to the demands of the hijacker and land as quickly as practical.