Brian White called for a new purge of HP's board.
Whitman said she regrets voting in favor of the Autonomy acquisition while insisting HP did its due diligence. That was an assertion echoed by Apotheker in a prepared statement.
HP Chairman Ray Lane, who joined the board when Apotheker was hired in 2010, didn't respond to an interview request Tuesday.
Mark Williams, a finance professor at Boston University and a former bank examiner for the Federal Reserve, called HP's accusations against Autonomy ``due diligence deflection''.
"Just to say `we paid too much because of fraud' doesn't negate the fact of inadequate due diligence,'' said Williams. "Some responsibility needs to come back to HP.''
At least one of HP's board members, McKesson Corp. CEO John Hammergren, has experience the aftermath of an accounting scandal. McKesson named Hammergren as its CEO after revealing it had been conned into buying software maker HBO & Co. for $12 billion in 1999. The accounting fraud wiped out half of McKesson's market value. The San Francisco company has since bounced back under Hammergren, but the comeback took years to pull off.
Investors are losing hope that HP will rebound because the company has made so many questionable decisions in the five years since Apple Inc.'s release of the first iPhone changed the way people use technology. The upheaval has reduced demand for HP's PCs and printers.
"I don't see how anyone could invest in this company any longer,'' said ISI Group analyst Brian Marshall, who described HP as "an unmitigated train wreck.''
HP's stock plunged $1.59, or nearly 12 percent, to finish Tuesday at $11.71. The shares haven't closed this low since October 2002 when HP was still facing a shareholder backlash over its acquisition of rival Compaq Computer.
That deal has turned out better than the acquisitions HP has made during the past five years under three different CEOs. In that time, HP has spent more than $40 billion to buy dozens of companies. In a reflection of how poorly the biggest of those deals have performed, HP's market value has fallen to just $23 billion. That's about 70 percent less than what HP was worth in June 2007 when the first iPhone went on sale.
In the last three months, HP has absorbed nearly $17 billion in non-cash charges to account for the diminished value of its 2008 acquisition of technology consulting service Electronic Data Systems and its 2011 purchase Autonomy. Last year, HP