The DFO at Brisbane Airport was evacuated after a threatening note was found in the male toilets on Friday afternoon.
Police were called just before 2pm as centre management evacuated shoppers, with security announcing over the loudspeakers that there was "a confirmed emergency".
Lezah Kupfer, who was inside the centre when the evacuation began, said there was mixed messages from centre management.
"The first announcement said 'we have a confirmed emergency, please evacuate via your nearest exit' and then within two minutes it changed to 'please evacuate via the food court exit'," she said.
"At first everyone was confused and then started saying 'but we're missing the sale'.
"But then shop workers started closing their doors and telling people to get out, so everyone started heading out. It was very calm and the centre was clear within five minutes."
Ms Kupfer said four police vehicles were on scene and a helicopter had been flying over for about 10 minutes.
However, shoppers did not linger, with the car park quickly becoming jammed with customers trying to leave. It was still gridlock almost an hour after the evacuation.