I think people lose sight of the fact that the short lease was included in the accounts 31/05/2014 at 18m
Somehow it often gets portrayed that the uplift is 48m it isn't. It is significant yes and it relates to the lease not ACL shares. Similarly the value of a lease in one business ownership isn't necessarily the same value in another business ownership
As the original lease was included in the accounts and formed a part of total assets acquired then CCC must have got the benefit of the value of the shorter lease in the share price. The lease extension did not exist at that point as anything other than an intention dependent on other events. Share value being the agreed value of all assets less all liabilities acquired. The effect that Wasps ownership might have was irrelevant to the value to CCC in 2014
The value of the lease in total increased because of different factors under new ownership, some of which were Wasps business plans, long term tenants (Wasps, G Casino etc), investment in the infra structure, length of lease etc
Would be very surprised if a valuation of ACL was not done prior to disposal of the shares, the fact that a different valuer might have a different opinion is not really material its just a difference of opinion. CCC can point to having taken time to get professional advice on the share values and to have been guided by that, ie proper process followed in that respect. It would be difficult to see how SISU could have access to all the information required to provide an alternative opinion, but it would only be an opinion in any case and wouldn't make the process wrong necessarily.
The loan from CCC was £14m and that was secured on all of the assets (tangible or otherwise) of ACL. So it was charged amongst other things against the value of the short lease £18m and ACL total assets were significantly more than the loan, based on the accounts figures. (around £25m according to the 2014 accounts - so was security really an issue?)
The latest valuation if correct at £60m could put the Wasps Group balance sheet in to a positive, depending on what else has gone on.