Know When to NOT Give Instructions
Despite giving instructions in the name of helping the person receiving instructions, it's vital to understand when to give the instructions. Simply giving instructions, however in the name of goodwill it is, at any point at any time, real time feedback, isn't always beneficial. In small cases, it might not harm anything. In large cases, mass destruction is unavoidable.
For example, driving. Someone sitting beside the driver, not necessarily a driving instructor, ought to NOT TEACH UNLESS EMERGENCY!!! That is, if there's a car that come straight for you, and you're sure the driver didn't saw it, go ahead and tell him to stop beside the road and let the upcoming car pass through. This saves you lives. DO NOT, and I really mean DO NOT, use soft messages like:
"hey, there's a car coming from in front of us."
Aviation has long ago tried this way of speaking, from the co-pilot to captain, and cause uncounted crashes. Ever since, direct instruction becomes the norm, and most emergency are avoided. You can always explain later. Explanation requires passing through the "slow part" of the brain, leaving no time to avoid the "should be avoidable if you'd give direct instruction".
And in other cases? These are you being nervous. Know that the driver might not be the most safe, especially new drivers, than experienced ones; but they do their best, even if they accidentally break some road laws, to avoid being crashed. In this period of time, if you'd give full instruction since they start driving, give them throughout so they don't have their freedom. Don't start giving instructions ONLY WHEN YOU SEE THEY DID SOMETHING WRONG!!! You're asking them TO KILL YOU!!!
Why? In case of emergency, most probably the driver already noticed, and their brains are taking precautions to avoid danger. Your motives to give instruction during emergency shut down their brain, and they can only do two things:
Push the fuel lever to max, so as to avoid anything. Since they can't think anymore, and their brain are still residued by their own safety routes, and their brain are disturbed by your instructions, their brain immediately choose to stop thinking and just go as it is, hoping luck can get them past. If bad luck, alas, you guys end up in the hospital.
Push the brake lever to max, so as to avoid anything. It's better to stop the vehicle than to move it. Again, the driver brain stops thinking, so he/she needs some time (about 10-15 seconds, if you stop speaking, OR IF YOU KEEP ON SPEAKING, INDEFINITELY LONG UNTIL YOU SHUT YOUR MOUTH) to clear their brain before they can restart and think of a strategy. In this case, if you're in a bad luck, someone else didn't press the brake lever and crash into you, alas, both of you end up in the hospital again.
Oh yeah, I'm speaking for the good of the driver, so the driver know next time. I need to speak it out, otherwise, he/she won't learn. Sparks sake! You should wait for later. These are NOT THE TIME FOR INSTRUCTIONS/TEACHINGS!!! You could always wait for later, when they parked the car, then you guys recall together and learn together, NOT DURING THE TIME. And you think your instructions could let the car avoid accident? In that case, you should just drive yourself, and not ask someone to drive you in the first place, or you're putting both of you in grave danger, the road to death.
And I mean this seriously!!!
In conclusion, seek out the situation whether it's useful for direct teaching or not. If you're in teaching mode, then teach from the start, give instructions from the start, so the driver knows they don't have to think for themselves, just follow your instructions from the start. If you don't teach from the start, refrain your urges to teach halfway: it's a bad idea to put your life in danger just because you cannot resist speaking out your worries. These teachings could always wait for later.
Remember, the recipient isn't a robot. Unlike a remote controlled car or you holding the steering wheel or a half-self-driving car that you give instruction by mouth, or whatever; these recipients are robots that just darnly follow your instructions without their own thoughts. Robots, being controlled by if-else programs, does not have residue to change from their control to your control; that DOESN'T APPLY TO HUMAN. Human, being a self-thinking being, are more occupied by their own thoughts than outer instructions; be it daydreaming or whatever, most humans can relax and yet do lots of things at once. During focus, they can stop thinking about other stuffs and focus on their specific thoughts to achieve the task at hand. And this limits to THEIR OWN THOUGHTS ONLY. Outer thoughts, a.k.a. instructions from another person, isn't immediately processable by humans. They have to first decide whether to follow through their original instruction or follow yours. Then, they have to think whether your instructions would lead to a better outcome than theirs. Then, in case to follow yours, they might not catch all of your instructions, so you have to repeat it after they clear their thoughts (someone in deep thoughts wouldn't listen fully to their surroundings, believe me). Robots follow a specific program, none of their own thoughts. Humans have to first decide whether to follow their program or your program, which isn't immediately available as they need to simulate within their brain, before deciding to clear their own thoughts and listen to your thoughts, or ask you to shut up and keep following their thoughts.
So, for the sake of your life, shut up and let the driver handle it, and only teach AFTER they parked.