I don't think that's true. The reps are frequently kept in the loop as to what is going on, just maybe not minute to minute occurrences.

It's called a negotiating committee, not negotiating MEC. The NC members must be empowered to make decisions within the bounds of the direction they are given. If at any point they cannot accomplish that OR feel the need to recalibrate their vector they will report back to the MEC as a body (they don't answer to individual reps, which is an important distinction to make) for clarification/direction.

If your rep has a problem I hope he does something productive about it like speaking with the admin and seeking support from the other reps to make any necessary changes...NOT sowing discontent among the membership because business isn't being conducted according to his individual liking.