If I hire someone to do X I trust them to do X. If X involves them getting in my house to do something while I'm not there I give them the keys. If they screw up I no longer trust them for X and I no longer trust them in general.
I'm not saying you trust someone for all the possible things under the sun.
I'm saying if I trust you for X and you mess it up I no longer trust you for X.
For example, just because you hire someone for one purpose doesn't mean they should have the keys to your house.