I'm not upset or offended, Jeff, and I'm very sorry about your friend. But I'll have to say I don't agree.
I just don't think the forensic experts or whoever does those tests and/or announces the results to the public would take the risk involved in creating a fake report. With all the press attention to this, the truth probably would come out eventually, and their jobs and reputations are at stake. Even if they cared about protecting Heath's family, I just don't think they'd go that far out on a limb to do it. Besides, I imagine Heath probably HAS used drugs (even heroin, if you believe those ubiquitous mysterious "sources"), so although none of us want to think drugs were involved in his death it wouldn't be a huge shock or blow to his reputation if they were.
If ... I don't know ... George W. Bush were found dead (god forbid -- seriously) and they discovered evidence of drugs, THEN I'd think they might attempt a coverup. But for Heath Ledger? No way.
Course, I believe Lureen, too.
As to whether the scene was "cleaned up" before the paramedics arrived is anybody's guess.
True. But if they'd cleaned off the $20 bill, they would have unrolled it.