The traditionalists imply that the reason for this is that...

The traditionalists imply that the reason for this is that, women are less reliable and of lower mental ability then men, however this reasoning of theirs has no support from the Qur'an and is an opinion borrowed from Jewish tradition. (See Deuteronomy 22:13-21 and Numbers 5:11-31) As far as the reliability is concerned, the Qur'an has required even of men to be two as witnesses instead of one.

Does that imply that Allah does not consider men to be reliable such that the appearance and testimony of one man was not considered enough? Are both men to give evidence? This is required only so that if one of them (the men) misses any detail then the other could fill the missing information and support the testimony. In other words, it is a legal way of supporting evidence.

The requirement of two men as witnesses does not imply that men are of low reliability or have deficient mental abilities. Two witnesses are required just to consolidate the evidence. Similarly, when two women were required as witnesses instead of one man, the implication should not be unreliability. It is only a way of consolidation of the evidence and not that women are less reliable. The Quran in other situations accepts the testimony of a woman as equal to that of a man.

In fact the woman's testimony can even invalidate the man's. The Qur'an ordains that if a man accuses his wife of indecent and un-chaste behavior, then he should solemnly swear five times as evidence of the wife's guilt. If the wife denies and swears similarly five times, she is not considered guilty and her testimony will invalidate that of her husband.

This is stated in the following verses: "And (as for) those who accuse their wives and have no witnesses except themselves, the evidence of one of these (should be taken) four times, bearing Allah to witness that he is most surely of the truthful ones. And the fifth (time) that the curse of Allah be on him if he is one of the liars. And it shall avert the chastisement from her if she testify four times, bearing Allah to witness that he is most surely one of the liars.