Extremely idiotic moment

When Ofelia is sneaking around in Vidal's office near the end of the film, she decides to randomly place the magic chalk on his desk just as he is about to approach it which makes him very suspicious and on edge. Then when he is drinking she somehow manages to move from his desk to a completely different part of the room which meant she would have had to sneak right out in the open, yet Vidal somehow doesn't notice even if he is in pain from the alcohol coming into contact with his wound. It seems like all this is done just in order for there to be a reason to insert the "Oh no, they're going to get caught! Wait, they're now in a completely different area" cliche into the film.

Is there any rational explanation why she would leave the chalk on the desk which would give away the fact that Vidal is not alone or that someone has been in his office? I've seen people speculate that Ofelia's other idiotic actions were out of her control and were being influenced by a higher power, but that doesn't make sense in this case as she was going to be found anyway due to the thunder/lightning which alerts Vidal.