61.385 mentions nothing about having to hold an instructor rating. Not sure where you are coming up with that? I don't think it is creating a "pseudo type rating". Type and class ratings are clearly defined.
By your logic, if a pilot friend asked you at the bar one night "hey, I've forgotten, what was the stall speed on (insert the plane we both fly)?" then you would be giving training!
61.1165e allows an instructor to obviously teach the general competency requirements of 61.385. If the list of privileges for an instructor didn't let them teach that stuff then that would be silly!
Yep you need an instructor rating to teach someone how to fly an aircraft that they are not allowed by regs to fly because of say, a design feature or the aircraft not being a type or class that they are licensed on, or to conduct a flight review.
I've had it clearly from casa that "training" (ie giving icus to) a pilot who is licensed to fly an aircraft we operate in our sop is not training that requires a flight instructor rating. The pilot has already been trained/reviewed/certified competent by an instructor already, hence why they are licensed to fly it. The operator still has to ensure they cut the mustard and are up to their standard.
It does get a little more complex though when you start having type ratings, OPCs, approved check and training etc all involved.
Thorny, just because he has 15,000 hours doesn't necessarily mean he knows how to check and train. Without any more details, this 15,000 hour guy might have 14,500 hours single, maybe some single turbine, have his 500 multi command, and maybe he has just put a jet on the AOC and wants to train people himself in that! All without ever being in a formalised C&T process himself.