Well done Corsairoz,
I've had the occasional pax comment along those lines about things various over the years and I'm always ready to meet and chat with the person involved. Found a bolt missing on the LE Slats once and in your case it sounds like a slight case of misrigging, which usually can be easily remedied, and wouldn't have been noticed on the flight deck.
I spoke with a pax recently about what he thought was an abnormality he noticed when the flaps extended. I spoke to the engineer and we extended the flaps during the turn around and indeed there was a fairing coming adrift, which was then rectified. I had business card from the aforementioned pax so I rang him and thanked him for the information. He sounded chuffed that I took the time.
Even if there was nothing untoward chatting with the pax and maybe setting their mind at ease is worthwhile
PR.
Regards,
BH.