Twice I've been cleared to cross an active runway by tower with an aircraft visible on short final and on another occasion had to abort because another aircrew acknowledged a clearance to hold short but kept taxiing right across the active with me on takeoff roll.
The lesson here is that everyone, pilots and controllers, can make a mistake and if you're not paying attention to what's going on around you and listening up for mistakes like these you're part of the probelm and not part of the solution.