The basic fact of the copyright infringement suit brought by Oracle Corp. (NASDAQ: ORCL) against SAP AG (NYSE: SAP) are not in dispute. A now-discontinued unit of SAP called TomorrowNow downloaded copies of Oracle software without paying for them. Beyond that, everything is in dispute.

In a trial that began yesterday in an Oakland, Calif. federal court, Oracle executives have claimed that TomorrowNow’s illegal downloads of Oracle’s software should cost SAP more than the $40 million that SAP has suggested as the cost to Oracle. Oracle CEO Larry Ellison testified that the intellectual property downloaded by TomorrowNow was worth about $4 billion. An expert witness called by Oracle stated that SAP owes Oracle at least $1.5 billion. Oracle is seeking $2.3 billion in damages.

Ellison’s estimate is based on his contention that the software could have cost Oracle up to 30% of the 13,000 customers of PeopleSoft which Oracle had acquired. In fact, SAP gained 358 customers as a result of the illegal downloads.

Oracle co-president Safra Catz characterized SAP’s calculation of $40 million as “crazy,” and called the amount “a reward for [SAP’s] bad behavior.” Oracle’s other co-president, Mark Hurd, was not employed at the company when the downloads occurred.

Hurd was then the CEO at Hewlett-Packard Co. (NYSE: HPQ), and that’s another story. But what is interesting is that Hurd’s replacement at HP, Leo Apotheker, was at the time co-CEO of SAP. Apotheker has given a deposition in the case, but Oracle has issued a subpoena for Apotheker to testify in person.

But HP won’t accept the subpoena and isn’t saying where Apotheker is, or even if the company knows where he is. Oracle has reportedly hired private investigators to find Apotheker, but Oracle’s attorney has refused to confirm those reports. Bloomberg quotes an HP spokesperson as saying that the subpoena for Apotheker is “no more than an effort to harass him and interfere with his duties and responsibilities as HP’s CEO.”

SAP’s stock, which set a new 52-week high recently, has lost about -5% since then, about half of it since the trial started.