I bet ya it was either alive and stunned or just recently killed when you passed it. Mine (non ascaris) were all flat, but most Ascaris pics i see flatten out when theyre dead too... and the pinworms flattened when they died after 5 hours in a jar.
I've read a story of a little boy passing one alive back in the 50s and the dad had to pull it out. I'd freakin die