We all make mistakes. I once forgot to include gravity in a pressure drop calculation for a 100 ft vertical pipe as part of a steam drum system. I had to send an awkward email revising the design pressure I previously communicated out.
But hey, if we were perfect, we wouldn't need peer review.
I have a little bit of experience with limit switches, but that's really interesting. It certainly seems like an unusual system. I'm a lot more familiar with safety relays.