Control Laser interview questions

Applied directly to HR from on-line job posting (email provided). Process took 2-3 weeks. I was contacted via email and scheduled for a phone interview. The phone interviewed was by a HR person, an Applications Engineer and then a third random person whose name and title I was never made aware of - maybe he was too important for introductions - a legend in his own mind; there a few out there who work by themselves since no one will ever work for them or with them. I was in the middle of getting clarifications for the JD from the applications engineer when "subject matter expert" guy jumped in and started asking question after question - an endless maze of questions to the podium of " who is smarter than a laser engineer".