Your quite correct, if there has been a tech delay there is always one passenger who believes they know it all and who has wound up the other passengers. I am always surprised when intelligent people tend to believe some of the drivel a stranger tells them. Then again as someone has said they are out of their normal environment and not knowing can be scary. I have always combated this by pointing out to any worried passengers that I am no braver than them and if I thought there was a problem with the aircraft I would be the first one off it. This retinal has, so far, always calmed any fears and made them see sence.