Why do you think it is a little harsh? I know stuff happens as well. But, someone has to take the responsibility. To me, the trainer is the one that needs to be held accountable. You could also have something in place for big operations where the assistant trainer is running the barn while the main trainer is at the main stable. For example, Pletcher could have a string in Cali but he would be in New York. The trainer over seeing the operation in Cali would be responsible for any positive tests. The training outfit has to say that they horses are running under the assistants name on behalf of Pletcher. There is always policy that can be well written to address all situations.