The thief didn't wish to be detained; therefore it was OK to shoot him.
That's the way I see it. Self-defense, end to end.
Surprised they had a judge on this case who is unable to think like a crook ~
Oh, please.
If I saw someone messing with my truck and he ran off, and then by some bizarre chance I saw him again an hour later with a police officer nearby and I said: "Officer! Arrest that man! He tried to break into my truck!" it would be purely my word against his and the would-be thief would walk away laughing.
I have never heard of someone returning to kill a witness who saw him trying to break into a car.
Even if your scenario was in any way plausible, you're still not allowed to kill someone because you believe that they might try to kill you tomorrow.