Yes, that would have been a better example to cite. It's exactly what can happen from engineer fatigue. The fact that it was transit rather than commuter rail is immaterial to the effect of fatigue.
Checkout the SYSTEM STATUS on SEPTA's web page.
Over a dozen train annulments due to "manpower shortage" according to the web site.
Is this opposition to the 6-day work weeks, or just normal engineer shortage problems?