I would never test how a job candidate operates under pressure.

Pressure is something you rise up to. Not something you employ for.

Leaders

handle pressure. They are the pressure valve that prevents the general 

employee

from having to deal with the 

pressure

 

You can't hire for that. An employee that you hired for predictable, manageable work can prove themselves and work their way up to accepting pressure and becoming a leader, but that's not something you should expect out of someone in an interview.