it can be called a computer error due to the bad computer interface design of the drop down menu In the pen and paper times you could call it a "form design er

it can be called a computer error due to the bad computer interface design of the drop down menu In the pen and paper times you could call it a "form design error" if the tick boxes were, for example, confusingly named "Yes, I don't want to divorce" and "no, I do" and someone misunderstood and ticked the wrong one