Gittin 5: Agents; Balancing Stringencies and Leniencies

We have learned that an agent must claim that he witnessed both the writing and signing of the get when he delivers that get to the wife.  What are some of the differences between what is said by an agent or messenger of a get and what is said by the husband or wife themselves?  The wife might be able to say the same thing; that she was witness to the writing and signing of the get.  But not a husband.  Why not?  The rabbis suggest that a husband might use that stringency to claim that he did not in fact witness the writing or signing of his own get, thus leaving his wife in a state of limbo as an aguna.

Another interesting juxtapositioning of lenient and stringent guidelines is introduced at the end of today's daf.  Bar Hadaya was an agent who insisted on inspecting every letter of the get as it was written to ensure that he would be able to answer questions honestly and accurately if he was challenged on his witnessing of the writing and signing of the get.  The rabbis warned against such stringencies.  They were concerned that husbands would use such practices to suggest that other gets were in fact invalid.  

Again we note that the rabbis are very aware that some men refuse their wives the get, essentially putting women in a situation where they risk forbidden sexual contact or where the husbands marry again without having divorced their first wives.  While multiple marriages were allowed by the letter of Torah law, they were forbidden by rabbinic law and they were only minimally acknowledged in Torah law.