(at around 44 mins) It is said that acetone is highly tenacious and residue would still be present on the handler. Actually acetone is very volatile. Unless someone had submerged his hands or other body parts into acetone for a considerable time, all of it would have been evaporated at the point the investigation reached this level. Also the discussed process that uses acetone and chlorine bleach, will produce very crude chloroform with side products like hydrochloric acid vapor, that may pose a direct hazard to the handler. Definitely, if the perpetrator had prepared chloroform previously, and not taken the raw materials with him to the scene to produce it while the victim was watching, he would be unlikely to have such an amount of acetone vapor around him that it would have absorbed into the wood of the canopy.
Near the end of this episode, Dr. Tara Price is seen taking a medication from a bottle labeled "OXYCODONE 150mg." This is over ten times the ordinary dose of oxycodone, and no such dosage delivery; tablet or capsule exists for oxycodone.
(at around 29 mins) You can clearly see the hanged man's eyes are open when his body is discovered. However, when the body is inspected by the CSI team (at around 46 mins) his eyes are shut. To shut his eyes would be classed as altering evidence, something severely looked against by CSI's.
In the opening scene, the gazebo buckled under the weight of the dead body hanging by a rope, but later in the episode, the gazebo had no trouble holding up the weight of a mannequin, the eventual murder victim and two teenagers simultaneously.