I’m not at the computer to check now, but you gotta consider that the music uses a sample from Cola Bottle Baby that was recorded in analog and most likely had transport drift when plagued in a different equipment. A lightly variation on the nominal speed can cause a fractional BPM.

When that is sampled and speed/slowed in software - specially at the time the record was made, you couldn’t get exact on the beat with a digital metronome.