For a moment, he almost chucks the idea out the window and stays. Maybe the shield will hold, and if it doesn't, maybe Cap and Iron Man will show up and actually be able to take the Skrull down.

He thinks about Billy, though, and the likelihood of him not doing something stupid to protect Teddy, and then he thinks of the ease and the speed with which the Super Skrull killed his mom, and he's off before he can even clearly think about which direction to go in.

He has to get as much distance between them as possible, and keep it that way. Nothing is worth losing Billy.