Good job understanding what was going on, and situational awareness is, as you've found out, very important. However if this guy is an ambulance pilot then this isn't his first ball game. I don't think calling the company or reporting him will do anything productive. Surely he realized his mistake but said his departure call normally because he is a professional. If you decide to stay in GA for decades like he did you will certainly see this many times and in other variations. Communication is very important. There's no such thing as overcommunicating or asking questions or giving suggestions on a CTAF. However dobbing someone in because you were scared is not really a constructive solution in my opinion. You should have raised the question before turning base with the pilot in question, not on the internet.