To start with, a period of four months supposedly passed between the time of the act of malpractice (a hip replacement surgery that ended with both legs amputated from an Olympic snowboarded) to the time of trial. Four months! Anyone who has had even the slightest interaction with America's court systems knows that nothing moves that quickly. Least of all a civil lawsuit involving detailed medical information that goes to a jury trial. Four years would be slightly more realistic.
But, I understand there are more important time needs in the story, so I'll move on. An even more flagrant problem, and one that had no requirement in teh story, was the confusion between a civil lawsuit, which this was, and a criminal prosecution, which this wasn't. The writers do not seem to understand something very basic that most Americans should know about their legal system.
There are two completely separate and different legal systems in our country. Civil cases are where people (or corporations or governments) sue other people (or corporations or governments) for some wrong. If the person suing (plaintiff) wins, they are usually awarded money.
Criminal cases are where the government (and only the government), whether state, city, or federal, charges someone with a crime. If the government wins, the defendant might be fined, and/or be sent to jail or prison, or in some cases even be put to death.
The terms used in each of these two systems are often different. And this is where Grey's Anatomy got so embarrassingly off-track. After the plaintiff's attorney finished questioning a witness, he exclaimed, "The prosecution rests." Since this was a civil lawsuit, there was no "prosecution." There was only a plaintiff.
SPOILER ALERT At the end, when the verdict was read, the jury foreperson announced, "Not guilty." Again, since this was a civil suit, no one could be found guilty or not guilty. Those terms are only used when someone has been charged with a crime.
There were several more minor errors throughout the show. Most of these problems could have been easily corrected by having a legal consultant read through the script and/or be present for filming.
The result of so many basic and easily-fixable errors was that the show looked poorly researched and inauthentic. If their medical errors are as bad as their legal ones, I have to seriously question this show's credibility. Not that a medical or legal show has to bee 100% accurate, but such basic mistakes can seriously undermine the show.