Hammond joined the club on 20th October initially until the end of January. This as we know was extended on 15th January. The Transfer Board was in place when Hammond was initially signed (chaired by Brannagan) and, in an interview on 26th October, JIm Phipps said (re transfers) -
"All such questions are left to our Technical Board (MD, football manager, FD, academy manager etc) to decide, provided they stay within board approved budgets and parameters.
In a thinly-veiled attack on previous manager Nigel Clough, he added; "That said, some of the current problems in the side (its size, for example) are byproducts of our trying as a board to be true to our approach, in circumstances where we allowed the Technical Board process to be thoroughly undermined by a gaffer who was not interested in the process; hence, some of the excesses (recruiting in quantity, signing injured players etc). We should have seen what was happening (the excesses anyway) and responded to them more quickly.
"In appointing a new football manager last summer, we specifically set out to find a gaffer who would help us re-establish a process that would prevent the repetition of the same mistakes. I am very happy with the progress we have made on this particular front and believe the fruits of the Technical Board process will show themselves over time, if we stick to the process."
The Board was overhauled on Dec 7th
"David (Green) is the owner of Renishaw based Green Piling Ltd and is a previous Chairman and Honorary Vice Chairman and his new role at the club will see him Chair the Technical Board, which directs football recruitment at all levels within the club.....
Also of Sheffield United Limited, Carl Shieber joins the Technical Board as Player Contract Negotiation Manager, and this is a function he has performed previously for the club.
Managing Director Malachy Brannigan will now leave the club with immediate effect after his almost two years in the post, and the Board wished to place their sincere thanks for all his hard work on the record."
I would be very surprised if Hammond's "extension" was part of his initial loan, more probably it came in January when the current Technical Board was in place.