He is obviously personally known to me.
The CA law regarding loaning of firearms can only apply to two residents of CA located in CA. You are a resident of NV. The CA law regarding loaning of firearms only applies to him, while he is located in CA. When the gun crosses state lines and the loan occurs between residents of different states, then the laws of the state where the loan take place apply, BUT ALSO the Federal law now also applies because the gun is crossing state lines and because the loan is occurring between residents of two different states.
The only thing that appears to be illegal is for him to walk around in possession of your gun, without you being present at the time, in his state of residence.