According to the Wall Street Journal this morning, Oracle - rather than IBM - acquired Sun because of "transaction uncertainty" among Sun's board of directors - mainly caused by Big Blue lowering its bid price from $10 to $9.40 per share, and specifying that the deal was contingent on other items and conditions.
Reporter Dan Gallagher notes that while IBM isn't mentioned in the filing by name, Sun's references to "Party A" and "Party B" can only refer to IBM and Oracle, the two companies involved in the dramatic first few weeks of April.
As we all now know, Oracle delivered an offer to buy Sun at $9.50 per share on April 17, slightly higher than IBM's downwardly adjusted offer. Sun's board approved the Oracle just bid two days later, on April 19. And that was the end of any transaction uncertainty, once and for all.