Generally, training in Krav Maga and Martial Arts is relatively safe.
If you are a qualified Krav Maga or Martial Arts Instructor, your training would've given you the tools to create a training environment that minimises risks and a teaching format that prevents injury. When these elements are carried out correctly, injury does not usually happen. However, Relying on something to never happen, isn't the best tactical approach - as with all things self-defence: Preparation is Key! That's why anyone who is in the role of 'Instructor' or 'Coach' in any self-defence, martial art or combat sport needs to have a basic understanding of what to do.