Is a marriage contract considered valid if it was concluded in the absence of witnesses, and the guardian was also a witness at the same time, or if the authorized marriage official (ma'dhoun) was both a scribe and a witness, and what are the implications of its invalidity if the husband suffers from amnesia?

The father's testimony for marriage is not valid, because the guardian's testimony is not accepted. The testimony of a mature Muslim servant is valid, as is that of the officiant if his role is limited to the contract procedures.

The marriage is valid in this regard. Some scholars have validated marriage with public announcement even without two witnesses. Therefore, the marriage is valid.