The MCAS system, at fault in the first crash, may be disabled via a cockpit control. In other 737s, moving the stick was sufficient to disengage it. For some reason, this was changed in the Max, and you must use the other control. However, any competent pilot would know every control in the cockpit. The captain of the latest flight to crash allegedly had 8,000+ hours of flight time.
If an aircraft begins behaving incorrectly, the first thing a flight crew should do is disable automation and try and fly it manually. That wasn't done if MCAS caused the crash. This was an emergency that developed over minutes, not seconds, and there's really no excuse.