You are right as only my job only approved 2391 testers can test (fully understand why) but it seems silly how this guy would need to be assessed again if he wanted to be part of the NIC...One example of the point of the 2391 is that when big Electrical companies look to take on electricians to carry out inspection and testing on large projects, commercial/industrial they tend to only employ sparks with it.
I've just been on a large industrial warehouse carrying out a periodic and it was 2391, 17th edition JIB Approved Gold card holders only.