Let's make sure everyone is on the same page here.
The OP was paid everything he is due. The OP has no wage claim here.
The OP was, in fact, overpaid. The OP has no legal right under the law to keep the extra money.
The other employee has a legitimate wage claim against the employer.
The other employee has no legitimate claim against the OP. The other employee is not the OP's problem.
However, if the employer wants the extra money back that the OP was paid in error and which the OP was not due, the OP does not have any grounds to refuse. How the OP repays the employer is between the two of them.