Tiffany just doesn't seem like she totally wants to be there, but I will give her credit for sharing her fish with Angelo. She didn't strongly dismiss the notion that Angelo likes to meddle in others dishes, however, she did back him by saying that each chef is in charge of what happens with their dish. You either stand up and make it clear not to touch it, or you believe that it needs something and your desperation allows you to let others try to find a fix for you. If you think it's good, or you think you know how to fix it, nobody throws anything in your food without you taking charge.
Still, it was a pretty lousy way for Spike to go. Like him or not, he put a dish out there.
ETA- Whether Angelo tries to screw people over or not he does need to learn how to back down a bit. There is a difference between helping and allowing another chef to follow their own concept all the way through. Sometimes if someone doesn't ask directly for you to help fix it you just need to tell them what you think is off and let them figure out what they need to add. He trusts his palate. That's fine, but maybe that's what led to Tiffany's "look" last week. Even if he's trying to remain modest he can sometimes come off as a culinary know it all.