In practice... Like in so many other schools and courses, some
critical lessons are only taught once, then trainees are given ONE
chance to try it out in the field, and that one time trying it out
in the field is ALSO an assesment. 
u are SO right about the assessment part.
As for MSG Ross...i tell ya so far for me in the army...he is the
ONLY person who can really strike fear in me...i get goosebumps
just hearing him shouting. He really won't give a damn who u are,
officer or not...but i really respect him, he knows his stuff and
is a damn good teacher...
regard the bpv...read in the papers the porcelain(or is it ceramic)
plate consists of 20 layers....during a test using a 5.56mm
bullet....it penetrated until to 18th layer or something....