I'm A Banana
Potassium-Rich
Let's say you had a friend like this in the real world. Would you trust your life to her ability to spot traps? Would you risk your life on her word if there were a means to accomplishing your goal that wouldn't put your life at risk?
I wouldn't.
Military units do this every day. "Sir, Intelligence indicates that the area ahead has no land mines." And then you act on that knowledge. You do trust the information of the specialists, when in life-or-death situations.
The only reason I can see that someone would make a different decision in an RPG is because they would know what her Search skill bonus was, that she took 20 and that the combination of those two things were more than enough to detect any level appropriate trap (and that the DM always presented the party with level appropriate challenges).
Or because their characters are heroes who take calculated risks as a matter of course, heroes who aren't intimidated by inoccuous levers.
OK, let's say you have the superhuman ability to survive getting shot in the face 19 times out of 20. Note the term SURVIVE. It still hurts you just as much as it would hurt a normal person. You still look horrible and feel horrible until it heals, you just can't die. Now let's say you want to buy a TV. The guy at the counter gives you an option. You can give him $500 for the TV or you can let him shoot you in the face and get the same exact TV. Do you honestly let him shoot you, knowing that it's going to be excruciating and that you have a 1 in 20 chance of dying? Or do you pay the $500? Or, if you don't have the $500, do you just wait to get the TV until you DO have the $500?
Depends on how badly I want the TV, and how brave I am. I'm no hero, and I'd definately consider being put in excrutiating temporary pain for $500. Yeah, it's bad, but it's only temporary. This TV will kick ass for YEARS to come!
Now, if I was truly heroic, and I had just stopped a bank robbery and saved the people inside with my magical power to survive getting shot in the face, and on my way home I cut through the park where there was a guy with a TV who was offering to give it to people who could be shot in the face, or for $500....I'd still say "Okay! Fire away random person!" And if he happened to have a kryptonite bullet that actually killed me, I would not be feeling heroic anymore.
The point is, there are easily available way to expose NO member of the party to risk. The fact that many players don't take those options (some don't even think of taking those options) is mostly based on metagame thinking about the consequences of setting off a trap (expenditure of resources and possible disruption in the flow of play) rather than in-character thinking (it will probably hurt, it may severely injure me and there's a possibility that I coudl die).
What does a hero do, send people to die in his place, or go to die in the place of others (knowing he's got the skills to survive where they don't)? Do I brave the unknown, or do I pay Little Jimmy the town cripple to go brave the unknown so I don't get hurt? Do I go explore dungeons for a McGuffin, or do I just bankroll some adventurers to do it for me? Do I fight the monster, or hide under the bed so the monster doesn't get me?
The characters, being heroes, don't choose the safest course of action. That's the point. Heroes survive not choosing the safest course of action because they're HEROES. You wouldn't, I wouldn't, even that military general wouldn't, but a hero....a hero would. No man in a book or a movie ever died from pulling a lever.