Even if a pilot does think the controller said, "Continue rolling", he should never take that as clearance to enter a runway. The phraseology for entering a runway is very clear; "Cross runway xx", "Line up and wait", and "Cleared for takeoff".
Even so, sticking to the standard "Hold short runway xx" phraseology will also help to prevent misunderstandings. Maybe a controller can comment, but I don't think use the of "Continue holding", followed by an incursion, would qualify as a controller operational error.
A lot of people ignore me, and others, when we advocate for the use of standard phraseology. Standard phraseology reduces the threat of errors such as this.