Love this post from Chris Sacca with advice on how to pitch business proposals to Google. With the attention Google gets, I'm sure Chris needed to vent about the volume of crap he sees every day!
Two points resonate for me, particularly in the world of larger deals where you have to keep working together after messing up like this: Don't go over the head of the person you're dealing with (unless you ABSOLUTELY have to), and don't think that threats are going to get you taken more seriously.
At best, these tactics will sour the relationship with the person you need to be your advocate in the company. Your deal may proceed, but in a hobbled state where it is hard to get anything done based on rapport with your counterpart. And trust me - that person will be looking for an opportunity to have their vengeance . . .