Bolleaux
"Ask him which engine is the critical engine on his twin, if he says the starboard engine he's talking **** as props rotate clockwise when viewed from behind on western aircraft types. If he says neither engine, ask him why as aircraft with counter rotating props have no critical engine. If he correctly answers the port engine probe him further by asking him why the left engine is critical and what happens if it fails at lower speeds such as just after take off, maybe then ask him explain asymetric blade effect. If he stumbles on any of this chances are he's blagging as all multi piston/turboprop pilots will know this subject back to front, our lives depend upon it in the event of a low speed engine failure! "
... What complete bolleaux.
A little knowledge can be a dangerous thing.
It is perfectly possible for an aircraft to be certified for a left-hand engine to be 'critical' for aileron control (for instance) and the right-hand engine to be ' critical' for rudder control... and vice versa. The engines' "criticality" varying with airspeed and configuration.
For engine also read propellor.