A very knowledgeable co worker of mine claims to have failed a rough inspection because of an MC connector being used in a box that is to be concealed in a wall. I believe it is a JHA vio. Any thoughts?

I would say there is a misunderstanding somewhere in the translation of the story, or a misinformed inspector.

Roger

Is he saying the connector is concealed or the whole box(cover not accessible).

Thanks Roger and Greg for your replies.
It was a plain old side bracketed deep 1900 box with 9 ko's (3 on 3 sides with no internal clamp)used as a switch location (mud ring added) NEC 2005 Art 330 does not mention any vio about MC connectors in walls or concealed locations.

I have heard folks claim that 90-degree MC, or flex, fittings had to be treated as an LB would be treated, and remain accessible.

Personally, I do not share this opinion. I do concede that some such fittings have little covers that make them resemble conduit bodies, but I still do not consider them to be the same as conduit bodies.

As for straight connectors .... I'm not sure it's possible to use them without concealing them. The NEC clearly allows for fishing the material ... and it's been quite a while since I saw a box with internal clamps.

I think it is confusion with the requirement that 90 degree FMC connectors stay accessible.

The only reason conduit bodies need to remain accessible is so you can pull in new conductors after the walls are closed up. You don't pull new conductors in a cable.

True Greg...or no one is going to make a splice in an MC 90 connector...imagine that!
Thanks for all the replies!