The due diligence was by all accounts a ****show. That's why Donald went back cap in hand back in Sep. 2019 asking for a bit more money off his share purchase.
If Short wasn't still owed his money for the shares, he could have just told Donald to **** off, but because there was still a financial interest, he probably didn't fancy any kind of legal/financial arseholery from Donald and decided to knock £2.4m off which was probably in the spirit of things. Almost certainly on the proviso that he couldn't come back for further issues, though, so with the Alvarez case taking a new turn, Donald now decides to hound the doctor.
The whole thing is an embarrassment to us, from start to finish. Suing the doctor for money that he almost certainly doesn't have, trying to bankrupt someone who acted in good faith on behalf of the club, is the final dollop of ****e on top.