I also came across this one when I worked in the sim industry (supporting army training). In my own experience, lots of sim errors could manifest in vaguely hum

I also came across this one when I worked in the sim industry (supporting army training). In my own experience, lots of sim errors could manifest in vaguely humorous ways, such as landing craft sticking vertically out of the beach when they landed, tanks whose turrets span rapidly, etc. These were usually obvious in testing. The more challenging errors occurred when multiple sims were federated together, since specific errors were often intermittent and might only be noticed when you could see the different screens together. Examples typically related to weapons effects and visual representations, e.g. platforms being invulnerable to missiles fired from a different sim, or a platform or person that looked different depending on which sim was displaying it. These issues were collectively referred to as 'fair fight' problems because it meant that trainees in one sim might have an advantage other others.