It's quite common that Bus outflow valve freak people out:
1) a non-pilot friend called me from a departure lounge telleing me that he just saw an Airbus passing by with some door open and asking me if he should alert the staff and make fuss about it. After a few guidance questions as to where it was/what it looked like I told him no...
2) Taxiing for departure an A320 had the same call from the tower - again, after 1-2 additional questions and a good look on the ECAM door page we elected to go.
Perhaps it's a good idea to do a good analysis of the problem before doing 180...
BTW, anyone remember this old chestnut:
Tower: "Airline XXX, it looks like one of your baggage doors is open."
Captain (after quickly scanning the FE panel): "Ah, thanks tower, but you must be looking at our APU door."
Tower: "Okay, Airline XXX, cleared for takeoff."
Captain: "Cleared for takeoff, Airline XXX."
Tower, during the takeoff roll: "Airline XXX, ahh ... it appears that your APU is leaking luggage..."
