After Bodo freaks out on the psych ward and is sedated, he is brought to the doctor's office for an interview. The doctor enters carrying a bottle of water and two empty glasses, opens the bottle, pours a glass for Bodo, and recaps the bottle. The doctor's glass, with water in it, then appears on the desk.
When Bodo shoves Sissi into the mud during the rain storm, she gets up and turns slightly and the back of her raincoat and the back of her arms are covered in mud. A few seconds later she stands and walks away and there's almost no mud. It is raining but not hard enough to wash the mud away that quickly. If you compare the amount of mud on Bodo's face and shirt in the same amount of time, there's almost no difference.
When Bodo is being interviewed by the doctor in the psychiatric ward, the doctor pours a glass of mineral water for Bodo, and sets the bottle down on the desk, with the label at an angle to the camera view. In the next shot, the bottle is turned so that the label is nearly directly facing the camera view. (The water happens to be Apollinaris mineral water, which is sourced from a spring in Bad Neuenahr, Germany.)
When Bodo leaps from the bathtub to chase Steini down the hall, Bodo clearly has not taken time to dry off. He should have left at least some trace of wet footprints down the hallway as he runs after Steini, but there is not a trace of wet footprints or any other water left on the floor as he runs. (It's possible that for safety reasons they ensured the actor's feet were dry before having him run on the tiled hallway, so as to avoid a slip-and-fall scenario.)