Lasgar

Their research and reporting covers that the stationary machines had massive issues as well due to improper maintenance, calibration, etc. Almost all of the overturned tests were from these supposedly much more accurate machines.

https://www.reddit.com/r/IAmA/comments/dszqp2/were_stacy_cowley_and_jessica_silvergreenberg/f6t6m8f/

Is it not most likely that they were built by a person?

Unless you know, someone was trying to make convincing evidence of bigfoot.