It amazes me when there is a forensic test that destroys evidence that the good guys always allow a small discreditable group of people to handle it alone. It's come up a few times in Bones when they recover a very small biological sample - just enough to run a DNA comparison once. When it comes to trial, all they have left is their report, and the lawyers on the other side insinuate that the evidence must have been fabricated because it no longer exists and only a few people saw it.
So why not, when such scant evidence is discovered, bring in a large group of third-party observers to the tests and preserve the whole process on video too? At least that way when the snarky prosecutor starts saying things like "if it even existed at all" the defense team can say "actually, over 30 other scientists observed the whole procedure, and we have three independent video records from start to finish, too".
Mokalus of Borg
PS - It would make me feel like someone is learning how to handle those situations.
PPS - The usual response is to be offended that someone would question your objectivity.