Is the marriage contract considered legally valid if the second witness was absent after reviewing the documents and before the wife's arrival?

If the shaykh officiates the marriage contract in the presence of one witness after the other witness has left, then the marriage is invalid according to the majority of scholars, because the officiant cannot be a witness to his own action. However, the Malikis consider it valid if the required number of witnesses is met before consummation.

As for the case where the shaykh's role was limited to writing and informing the two parties of what they should say, and he was not the one directly officiating the contract, then the marriage is valid and sound, as he is considered one of the two witnesses.

And if the marriage has fulfilled its conditions of validity, namely a guardian, two just witnesses, and a form of offer and acceptance, and one of the witnesses was absent only at the time of documentation, then the contract is valid, and there is no harm in the witnesses not being present during documentation.