Off-topic real safety question

Good Catch! My first flight on an airliner was on a United DC-10 in 1979. It was right after they were back flying again after their grounding fromn the AA Flight 191 where the engine fell off. This was actually a replacement plane as this was a charter flight to Las Vegas and it was suppose to be a DC-8 stretch, but because of mechanical problems, the DC-10 was used instead. I was sitting at a window seat, with a view of the left engine. What startled me was how much the wing and engine swayed and flexed in flight (This was my first flight) Then As I walked around to the other side I noticed the cowling off the supporting Pylon on top of the right engine. Since I knew the left engine had it on, and it was right after the DC-10's were airborne again after the AA Flight 191 crash, this got me a little worried. It also got my father a little nervous, so he asked the FA about it. Unlike your experience, she just shrugged it off and said that maintenance must have had it off for inspection. She never took it further or notified the cockpit. To this day, I always wondered if it was safe to fly that way. I have flown on DC-10's 4 times after that and not once was that cowling been off, and in no wing view photos I have seen, had it off.