Hooligan: yeah, but as you said it was someone landing at the wrong airfield - so the big issue is not the one under discussion here in that case, as presumably he/she would've been talking to the WRONG TWR, leading obviously to exceptional risks due to a failure of navigation.
But I take your point that one might not visually pick-up absolutely everything that might be about to cross the runway - fair point (but you'd hope if TWR had cleared e.g. vehicles across the RWY that he/she then WOULD be talking to the traffic on final!?)
