If someone is unknowingly carrying a loaded gun while driving someone else's car, could they be held responsible?

I told my boyfriend who's a felon that he could take my car to give his mom a ride, but I forgot I put a loaded gun in my car and he got pulled over and was taken to jail for having it. I put it in my car while visiting her so my kids wasn't around it. I feel so bad because they said he will serve some time for this offense. Is their anyway he could get out of it since he didn't know and it wasn't his car? I don't want him serving time for my relapse of mind.