Sorry, you're wrong. Depending on what the tech is it's absolutely possible to target an individual helmet, even if it's just dumb radio waves.
And how do they know for sure he'll use a backup helmet?
And even if they anticipate he might, doesn't wearing a non-fitted and strange helmet introduce some confusion into the situation?
Dude, it's OK that this isn't your area of expertise. Just admit it.
But hey, I'm sure you're right. The Saints, and Sean Payton in particular, would NEVER try dirty tricks. No. Never.