Obviously the Buddhas do not cause any persons death, even the one that try to steal a statue of a Buddha. What probably happened is that the karma for one's life as a human ended, either coincidentally while stealing the Buddha statue or the act itself trigger a negative karma to ripen. According to the law or karma, the act of stealing will cause poverty in the future.
I suspect the deaths are coincidences, but one of the last acts before one's death is stealing Buddha statues, does not bode well for one next rebirth.