Can rough roads create a suction from the water tank vent?

If I fill my tank all the way to where it comes gushing out the fill opening, yes when I hit the road it sloshes around and comes out the overfill and down the side of the RV.

I make a point of NOT doing this anymore because of the concern of other people/cops when you pull in to fuel up and they see something dripping from the MH and need to point it out to you and ask concerning questions. :R