I always give feedback to my students. Sometimes the 'Well, how do you think that went?' get's them to pull out the bad bits for themselves.
If I'm debriefing, then it's 'knock-em-down' then 'build-em-up'. Always end with the positives - well not-quite, end with what's next and a thank-you.
If your instructor isn't debriefing - he's not doing his job properly.
DD