Get ya A$$ down before refueling

This morning, while riding on the way to work, my bike hit reserve, so directly turn into a gas station near my workplace.

Before i could remove my gas tank cap to refuel, this station attendent shout across to me, at first, I couldn't understand what he was shouting at, as I have my helmet on.

Then I realise he ask me to get my a$$ down, before refueling, so I also shout back to him "huh, what??" (but continue to start refueling)

Later, he shout again, asking me to get down, then i replied: " it will be done within minute" but that uncle start to get angry. I ask:" why do I need to get down?" (still refuleing)

He replied:" you go inside and ask why lah!" , I replied:" uncle, you walk to the other side lah."

He replied:" I kana F by the boss inside, and thought I never ask you to come down!" (I still refueling)

Then i replied:" thats why I say you walk to the other side, you never see me right." (my tank is filled)

He just walk away, before i ride off. I don't understand why do I need to get down, I guess because of safety? But that uncle's attitude is nicer, I would have done it.