Depends how you were caught. On your back reaching up? No. On your knees? Yeah. Consider that this tag was placed in the wheel well, which doesn't require getting on your back and would only take a few seconds. It isn't like someone is there for a significant period of time. Especially since you can then produce said AirTag after inquiry and people will generally believe the claim even if suspicious. All you have to do is create _reasonable_ doubt. That's different than _certain_ doubt. This is because weird stuff like that is much more common than nefarious acts (though we remember nefarious acts more easily). I think you are likely overly estimating yours and the average person's awareness. Scam artists and magicians exploit these kinds of effects frequently and with an extremely high success rate.
Well if you were caught squatting down, with your hand literally in the wheel well of the car, again, that makes it pretty hard to argue you dropped something there. That's what we're talking about here.
Your hand is in the wheel well for a fraction of a second, just enough for a magnet to stick. You can still say "oh I was just picking up my air tag" and it'll be fairly reasonable. I'd buy it if it were done so you didn't look like you were fiddling with the car too long.
Your argument isn't very convincing. AirTags are one of the few location tracker that the public can recognize by sight and identify its use. This makes AirTags much less effective for use by malicious actors than other generic black-plastic case electronics.
My friend just had someone jack up his car and hack off a catalytic converter with a hacksaw in broad daylight, to steal it. How long does it take to place an airtag, 3 seconds? I think the chances of you being caught placing an airtag are slim to none.
A bit of an off-tangent: does your friend live in Seattle? Because catalytic converter and bike theft in broad daylight have become a staple here, but it is definitely not the norm in other cities.
So I wouldn't judge how easy it is to do something like that in general, based on a city where the prosecution is notorious for letting all kinds of criminals get released the morning after, which leads to the police not bothering with "minor" crimes like this (i.e., what's the point, if they will just get released the morning after and you waste both your time and the department time).
Catalytic converter theft is big everywhere, unfortunately. It's most common in larger cities, but it's worth the effort for thieves to travel out of town as well.
Cat theft, and petty property crime in general, is way worse in the cities that decline to prosecute which basically boils down to "the west coast and a few pinpoints on the east coast."
I hear this opinion (or something like it, basically that property crime is only an issue in the west because city governments are not harsh/violent/punitive enough) repeated often.
My anecdata: I live in a city where cops can and do whatever they want to people without serious oversight. Petty theft is met with both maximum violence and prosecution. it does not seem to have much effect on crime rates.
Washington, DC, does not decline to prosecute, but there was a rash of catalytic converter thefts in my neighborhood not that long ago. I'd have guessed that these thefts are tied to the popularity of hybrid vehicles, in particular Priuses.
I can't make sense of what's going on with prosecutions there, sometimes I hear about people getting away with major crimes, other times some poor sod gets charged for possessing 'material useful to terrorists', The Anarchist Cookbook, which you can buy on Amazon.
It's only less effective if it's somewhere that can be seen. I think most people don't check the insides of their wheel wells more than, well, at all. In which case the device could be neon green and it wouldn't matter for the purposes of visual detection.
You clearly have near 0 relationship with the public. The public can't identify an AirTag; most have hardly heard of the thing. And even if they did, someone's story of dropping a thing would convince 99% of people who want to be doing anything else than running BS detection on some weird person they've happened upon.
