Rijkman Groenink, chief executive of ABN Amro, faced a Dutch court on Saturday as "a lawyer for his own company" to claim that the biggest bank in the Netherlands had become a "toy for hedge funds".
His extraordinary outburst came as the bidding battle for ABN reached a climax two months after The Children's Investment Fund, an activist hedge fund, began agitating for a break-up of the 183-year-old bank.
His words capped five hours of high drama during a rare weekend hearing of the Amsterdam Enterprise Chamber.
The court must rule on a petition from VEB, a Dutch investors' group, to halt the sale by ABN of LaSalle, its US bank, to Bank of America. VEB claimed the sale - which was agreed with BofA in just four days - was "unlawful".
If upheld, the case would throw wide open the bidding war for ABN, which faces competing offers from Barclays, the UK bank, and a trio of European banks led by Royal Bank of Scotland.
The lawyers, advisers and bankers lining the olive-green benches before Judge Huub Willems heard of strained relations between Mr Groenink and Sir Fred Goodwin, chief executive of RBS.
Johan Kleyn, counsel for ABN, told the court Sir Fred had snapped: "I am not here to be cross-examined" and then bluntly told Mr Groenink: "it's none of your concern" when questioned about the consortium's plans during a conference call on Wednesday night.
VEB described the sale as a hastily-arranged "poison pill" to frustrate a higher break-up bid by the RBSconsortium, which includes Santander of Spain andFortis, the Belgo-Dutch group. VEB wants the sale put to a shareholder vote.
But halting the sale could leave ABN open to a claim of damages from BofA, which has agreed to buy LaSalle for $21bn (£10bn) in cash unless there is a higher offer by midnight on Friday that it is unwilling to match.
Hans de Savornin Lohman, counsel for BofA, told the court: "If the deal falls apart Bank of America would be compelled to file a substantial claim against ABN Amro."
If that happened, said Paul Olden, counsel for ABN, "with [legal] claims pending the offer with Barclays will not go through".
Unwinding the sale of LaSalle is seen as crucial to RBS and its partners, who can pay more for ABN than Barclays but only if the deal includes LaSalle.
"It must have been clear to ABN Amro that the sale of LaSalle would form an obstacle. The intended consequence was to stop the transaction of a potential bidder," said Jurjen Lemstra, counsel for VEB.
ABN denied the claims, as did Bank of America and Barclays. Duco Oranje, counsel for Barclays, said: "The idea that such a cunning plan existed has not been proved at all."
Lawyers fanned themselves with sheafs of paper as the temperature in the courtroom climbed and the tension wound tighter.
"This will be a hot summer, with, most likely, proceedings in the Netherlands and in the United States," said Mr Oranje. "This is an unacceptable situation. Banks exist in order for there to be trust in them.
"The theme was picked up by Mr Groenink.
"Banking is about people," he said. "It is a matter of trust and confidence. We have behaved decently throughout."
"I trained as a lawyer but I never thought I would have to stand before you as a lawyer for my own company. This is a very sad occasion. ABN has become the toy of hedge funds and I deeply regret that."
But tension was maintained as Judge Willems chose to rule on Thursday afternoon, just 32 hours before the deadline for the bids for LaSalle.