Quick Google search throws up the following and begs the question what kind of contract (if at all) did Hamilton actually offer Ferguson ?
https://spfl.co.uk/docs/067_324__therulesofthespfl_1375800603.pdf
Relevant pages would appear to be 43-46 and this clause looks fairly fundamental to it all
In the event of the two Clubs concerned not reaching agreement on the amount of
any Compensation payable, the new Club must, on the date of Registration or, if
later, on the date of any first offer of Compensation, pay to the Player's former
Club at least 50% of the highest amount offered or, as the case may be, offered,
plus VAT at the standard rate. All offers of Compensation shall be in writing and
shall be copied to the Secretary by recorded delivery post when they are sent to
the Player’s former Club. In the event that the amount of Compensation ordered to
be paid by a Compensation Tribunal is less than the amount previously paid in
terms of this Rule F9 or if no Compensation is ordered to be so paid then the Club
which has received such payment shall be liable to forthwith repay as a debt the
amount overpaid or, where no payment is so ordered to be paid, the amount paid,
to the Club which made such payment.
So that makes it all totally crystal clear then