from what I was explained, apparently (please take note of the "apparently") and according to fansites and fans present at the airport, everything was planned to tease??? fans. a dancer tweeted they would leave Korea, so fans went to the airport, of course. there was a van, but there were no bap members inside but only staff. staff filmed fans (maybe for bap attack or something else), and a manager (apparently Kang) said goodbye while he opened the car window.
A fan found bap later inside the airport; at that point some fans had given up already and chose leaving the airport, but others followed them; and from fansite masters' tweets, after fans followed bap inside the airport, the rude situation happened: do not take pictures or videos, do not wave to them, etc.