I think Leb had it right earlier - the Trustee draws a line in the sand and uses that to govern the disbursements they send out. That gets things pretty close, but brokers then make the final apportionment of the monies to actual holders of the shares in street name based on the ex date.
Usually there is not a big delta, but the long wait on the final distribution for MOSH means that considerable trading, and changes in ownership and entitlement to any final distribution, may have and in fact has occurred since 2/22.