I recently watched a tri (in a lake) of elite men, 100 of them, almost every single one of them was disoriented and looked dizzy getting out. Especially the ones who swam really hard. I would think it would be natural to be dizzy, you are going from a horizontal position with a different dynamic of balance to a standing one, just the visuals alone are confusing without talking about the change in muscle activity...on top of that people are RUNNING from the lake, ocean, pool, to the next event. This is what makes triathlon what it is, the transitions, as in, transition of balance, muscle, visual, everything. It is like putting or taking off somebody else´s prescription glasses, the brain must adjust, and the difference is the speed with which it does it.
I would think that if someone were NOT dizzy, they either slowed down and started changing the muscle activity before getting out of the water, or have learned through constant repetition to change the focus so quickly that they are ok.
Like I say, the elite men looked dizzy and they TRAIN hard to get over that transition.