Sometimes you have the right contract, but an attacker is making you pass in different parameters than you think. The most popular hardware wallets don't help you with this; the Ledger Nano S for example just alerts you that you're passing some kind of data to the contract, so you're relying on your computer to show the details. This is a problem when, for example, you're interacting with a token or wallet contract, and you think you're telling it to transfer $ to Alice, but actually it's $$$$ to Bob.

But there are better options with larger screens, which actually display contract parameters on the secure device.