[dcohio]

Pass-Pass-Pass*-

Partner started thinking about what he wanted to open... at this point, player in third seat who didn't realize he was in third seat when he passed said "Oh I didn't mean to pass, I wanted to bid" and he laid down a 1♠ card.

We called the director and he told the director he wouldn't have passed his hand in 3rd seat, and that he didn't see his partners initial pass. Director ruled that he could bid.

We argued that a misbid due to mechanical error (pulling 1NT instead of 1S) is allowed to be changed, but one due to mental error should not be allowed. We also argued it was impossible to be mechanical error as pass cards and suit cards are in different sections of the bidding box.

Who is right?

[campboy]

If he wanted to change his call because he wass under a misapprehension about the auction, the original call was not unintended (it was what he intended to do when reaching for the bidding box), so law 25B applies -- LHO may accept the change, but if he does not the pass stands and changer's partner may not choose from among logical alternatives one which is suggested by the (unauthorised) knowledge of the attempt to bid 1S (law 16D). If the change is accepted, the fact that he originally passed is similarly unauthorised to partner.

I would not say it is impossible to be inadvertent if the calls come from different sections of the box, just very unlikely. Here, however, the player's comment makes it clear that it was not inadvertent.

[peachy]

The player did intend to pass, his own words tell us that he did. At the time it was his turn to bid, he was having a "senior moment" and he did ot see that he was in third seat. Senior moments are not protected by the laws, mechanical errors are.

Some judgment cases exist but this is not one of them. Pass stands and his partner is under UI restrictions [not allowed to use the knowledge 1S was opened, nor the knowledge that his partner didn't see it was third seat].

[greenender]

And possible lead penalties, of course.

[Gerben42]

Agree. If he saw the auction incorrectly, the Pass was intended.
In general, mechanical errors don't go from one compartment to the next (there is some stuff with stop or alert of course, but that's not the case here).