Gas pouring out of filler neck

[thebebop]

Ok so this morning I fill up my 55 2nd series. I never top my cars off. When the pump clicks off I stop filling. This afternoon I go our to the shop and there's a strong smell of gas. I notice some gas on the ground next to the truck right under the gas cap. So I open the cap and a whole bunch of gas spits up and out of the filler.

I realize the heat will cause expansion but I've never experienced this on any of my previous vehicles....any suggestions on why this is happening? Or is it normal?