My thoughts as well- I've seen people who are amazingly well trained glitch due to other stress and exhaustion, and they try again and again until they are just making it worse. If anything, I've seen it happen at least as frequently, due to cockiness.

Training and determination make it less likely you'll "choke", or at least choke when it is convient. But no one is every going to be able to say they are 100% sure they won't freeze, hesitate, or in some other way just make the situation worse.

Just have a human failure factored into your plan.