I assume you're exaggerating slightly and that you mean "couldn't code as well as the resume suggested". How certain are you that the pressure of the interview (which often means broken concentration, poor sleep the night before, etc) and the unfamiliarity of the setting (even typing in a Google doc without proper spacing, syntax highlighting and auto completion can be incredibly disorienting) aren't a major factor? Isn't it conceivable that some worse coders are better under such circumstances than a great coder who suffers mightily under them?