Any plan was to deal with those who violated the sanctity of his home and was only active within his home. The only thing arguably premeditated was to shoot intruders, which is not necessarily lethal - to wit the finishing shot.
A mantrap even when set up within ones own home is illegal, whether it is lethal or not. The lethal shot sealed the murder, the premeditation to do so certainly crossed the reasonable doubt threshold with the amount of effort the prosecution showed he went through to entice the break in to occur while he was at home. (leaving boxes of expensive equipment at curb to be seen, parking blocks away so no one thought he was home, etc etc etc) then when you get the audio of his actions, and his own words after the fact, there is no doubt his entire intent was to kill. Premeditation.
I don’t see any way given the evidence as reported, that the beyond a reasonable doubt threshold was not met by a country mile.
Premeditated Murder.