Ah tc300mag1, that is precious!
You don't have gun rag reference to talk about the alledged court case where the handload issue came into play. No biggie. Nobody does. Gun instructors all across the country pass on this stupid myth on the CHANCE possibility that it could happen, even though nobody seems to know of any actual cases where it has happened. This is an Ayoobian myth that has been around for at least 25 years and it comes up time and time again and nobody has any court cases to substantiate this myth.
Either you had the right to use lethal force or you did not in a self defense shooting. If you did, it doesn't matter whether the load was handload, factory, or whatever.
Also, if you are believing that somehow the handloads could indicate premeditation, that would no more be the case than having the gun on your person or having actually loaded it with ammo. Additionally, the lawyer could just as well argue that you loaded your gun with the evil factory ammo that was developed to cause the most damage.
The liability is not in whether or not you loaded the ammo, but in whether or not you shot somebody.