The bottoms of spray cans are shaped the way they are to help hold in the pressure inside the can... but if you overheat the can and the pressure increases too much, the contents will want to expand somewhere, and that somewhere is the can bottom popping out under too much pressure for it to hold back.
The paint seeping out below the spray nozzle is due to a partially clogged nozzle. When you push down the nozzle, if it's not clear enough to let the paint flow, the paint will find another escape route... and that's between the stem of the nozzle and the top of the can. But that yellow goop (propellant?) leaking out at the bottom? That seems like a manufacturing defect, not "user error," and I would think that Testor's owes you a refund. I would call them and ask; it can't hurt to try.