Whatever you wanna call it.
I don't think it was unrealistic. How I view every scene is "is there any chance of this happening ?" If I get the answer yes I accept the scene. I am not here to try and reject everything I can. If there is a situation which can go either way, I'd rather believe in the side which makes the scene acceptable rather than taking the side that it is not. If there is a scene where I don't even see an ounce of possibility, I'll reject it.
Because even a remote chance of something being possible makes it realistic. And from all the stuff that one sees and hears these days, each and everyday you find something that you would never believe was true but it is.
Also if that part was unbelievable to you, you always have the other two options. They are just as canon as this one. You have options just so you can choose the one that you believe is the closest to realistic. So if you think hiding behind the tub was the best choice, that's your reality.