I'd assume the onus would be on the bidder to prove they have...

I'd assume the onus would be on the bidder to prove they have offered 'fair value.' The holder would simply request that the bidder come back with an independent valuation. That wouldn't necessarily require a QC. Hypothetically speaking.

As for them saying it will take 'some time' to receive the funds. I'm sure it would be written in legislation how long they have to pay up. I don't know personally, could be 14 days, 1 month? They are playing games by saying 'some time,' they'd know exactly how long.