Situational Awareness states avoid, not approach that type of situation. As to your friend’s negligent discharge, that is a training issue, not a chambered round issue. As @Todd30 pointed out, the Four Rules (now 3 based on revised NRA training), are designed to keep everyone safe. One must break more than one rule to endanger someone/oneself. Chambered or not, your friend was not safely handling the firearm. That is not an excuse for you - nor anyone else - to not carry chambered. If one gets into a bad situation, while adhering to Situational Awareness, then one is already well behind the curve, and the more time it takes to defend oneself, the more likely the encounter will end badly.
The reason for chambered carry is to give oneself the most advantage possible in a very bad situation.
As another poster mentioned, it’s your choice. Choose wisely, my friend. You and your loved ones are worth it - at least me and mine are.