I had mixed feelings about this story, mostly based on personal bias. I don't care for irrational people, be it in real life or in stories, though in this case it is central to the storyline. The cold, calculating psychopath I can relate to, but temper tantrums are beyond my comfort level.
Disclaimer aside, that same irrational personality does suit the first-person narrator. Reaction without considering consequences, rash statements (at the end), the outbursts, all define the antagonist as a major mental case quite capable of inflicting everything described.
After I read the story, my very first impression: this reads like an old-time radio script from the 1940s, with the sound effects marked in italics. Sort of a Tales from the Crypt type of story that somehow made it past the network censors. Good, bad? Neither, really, just different.