Fried garlic turning black
garlic burns very easily and is very smelly when it does.

If you are just sauteing then you should cook at a relatively low temperature and take it off the heat as soon as it is translucent.

If you are toasting the garlic then leave it on and watch it closely. Stir often and take it off when it is just golden.

If it burnt very quickly then I would agree with you that your pan was too hot.