You've not indicated anything where Patel would apply here. You'd have to show he was denied some process in his deportation that US nationals should have been accorded. I suspect that since they knew he was a permanent resident at the time, that such did not happen. There's not any strict prohibition of deporting permanent residents who commit aggravated felonies. The fact that he applied for naturalization means squat until he actually gets naturalized. Even then a court can in some cases strip him of his citizenship and deport him. You're going to need an experienced immigration attorney to look at the actual facts.