I have to agree with Cyclic Hotline, most operations use hot refuelling every day without any problems.
In the Southern North Sea, it used to be done regularly between flights for different customers onshore as well as on offshore platforms. It was rarely done with passengers on board unless the winds were very strong requiring ballast during the deck turnaround.
I do not believe that there is any significant statistical evidence to support the contention that it is dangerous.
LE