[twcho]

After a few tricks, declarer led from his hand ♣4, LHO followed with 9, dummy with 7 and RHO won with J. However, when RHO shifted to ♦4, LHO led his ♣K at the same time thinking that he had won the previous trick.

Now, what are the options that declarer can pick?

[pwg7]

twcho, on 2013-March-08, 20:10, said:

After a few tricks, declarer led from his hand ♣4, LHO followed with 9, dummy with 7 and RHO won with J. However, when RHO shifted to ♦4, LHO led his ♣K at the same time thinking that he had won the previous trick.

Now, what are the options that declarer can pick?

Law 58 A. Simultaneous Plays by Two Players

A lead or play made simultaneously with another player’s legal lead or play is deemed to be subsequent to it.

RHO's lead is the correct lead - LHO is deemed to have played to that lead. If LHO had a ♦, then this would be a revoke and must be corrected. leaving the original play (K♣) as a major penalty card.

[Vampyr]

Law 58A:

Quote

A lead or play made simultaneously with another player’s legal lead or play is deemed to be subsequent to it.

So declarer has no options if the leads were really simultaneous. The correct lead counts, and the card led in error becomes a major penalty card.

If the incorrect lead is made before the proper one, declarer can opt to accept the former, in which case the latter becomes a MPC.

EDIT: Sorry crossed previous post.