Plot hole: Meredith is subjected to a random drug test at work. However, the drug test is announced late at night. Tru is already working her "graveyard shift" at the morgue, so we know the regular workday is over. Hardly anyone would be in the office. Therefore, it doesn't make sense for the company to be administering this drug test, said to be requisite for all employees, at that time.

Factual error: Davis tells Tru that glucagon is a substitute for insulin in diabetic emergencies. In actuality, it does exactly the opposite of insulin, raising glucose levels in the blood while insulin lowers them.

Plot hole: How did John expect to get away with killing the other five men? He had made the plans for the party and booked the hotel room himself, so even if he disposed of the poisoned ice after the other guys died, his guilt would have been obvious, as the only survivor.

Plot hole: When Lindsay brings Tru breakfast in bed on the second version of the day, she is excited that Tru remembered her birthday, and she also mentions that nobody else did. But it's still very early in the morning. It's not at all reasonable to assume that anybody forgot her birthday just because they didn't call before 8am.

Plot hole: Meredith ensures she gets a negative drug test by providing some else's urine sample. Wouldn't they know straight away? It is good medical practice (something that a law firm would most likely want upheld) to check the temperature of the sample (about 32-38C) to ensure the sample is fresh.

Plot hole: John is slightly surprised to find that Tru is acting as bartender for the party, but doesn't dwell on it any further once she explains that she was supplied gratis to make up for the earlier "problems" with the room. But John should actually be extremely alarmed to find her there, given that he poisoned the ice and expects the other guests to drop dead. He certainly wouldn't want any witnesses to that.

Plot hole: Tru thinks that the alcohol has been poisoned, and doesn't realise that it's really the ice until she sees that the stripper has been drinking tequila without ice all night and is fine. But she should have known that the alcohol wasn't poisoned as soon as she found out that one of the men wasn't drinking any alcohol but still died, which happened earlier.

Plot hole: Luc arrives for his job interview at the Sheriff's while Tru is at the bachelor party. However, the clerk at the hotel told Tru that the party started at 7pm, so we know it's at least that late. It doesn't make much sense for Luc to have a job interview at that hour.

Plot hole: When Tru goes to the workplace of the "groom" to try to get him to cancel the bachelor party, he thinks that his "fiancee" Robin sent her to spoil his fun. But why would he think that? We found out later that Robin dumped him three months ago and there is no wedding at all. I'm sure Robin is pretty far from caring whether or not he has a bachelor party.

Plot hole: Meredith submits to the drug test at her office. In the next scene, which takes place later the same evening, Harrison tells Tru that Meredith's test came back positive and she was immediately fired. But it takes at least 24 hours to get a result from a urine test at all. If the test is positive, the sample must be subjected to a more thorough examination. It usually takes at least 72 hours to get the results in that case. There's no way Meredith's positive results could have come back in less than six hours, even if a lab had been open late in the evening.