Abbott, who last month returned fees of A$181,000 (£65,000), paid on the day before HIH collapsed, claimed he had no idea of the imminent liquidation until after the cheque was cleared.
He said he first discussed insolvency with McGrath after 6pm on 14 March, over two hours after the invoice had been submitted. But McGrath said he gave Abbott a copy of his draft report at a 10am meeting on 14 March and did not recall any further conversations with Abbott that day.
Blake Dawson lawyer Ray Mainsbridge said his notes showed Abbott was present at the 10am meeting and was presented with a draft report on the liquidation.
The firm also invoiced HIH on 14 March for A$1m (£359,000), which it has since repaid with interest.
The commission was closed after 220 days of evidence, but Mr Justice Neville Owen intimated that there may be further evidence to come.