Unreviewable remand order after joinder

In Fontenot v. Watson Pharmaceuticals, a long-running products liability and medical malpractice case about a transdermal pain patch, plaintiffs sought to add nondiverse health care providers to the case after removal.  No. 12-30711 (June 10, 2013).  The district court remanded pursuant to 28 U.S.C. § 1447(e).  The Fifth Circuit dismissed for lack of appellate jurisdiction, concluding that a remand for lack of subject jurisdiction was unreviewable under Thermtron just like a jurisdictional remand under 1447(c), and noting that all other circuits facing the issue reached the same conclusion.  The Court also found that the joinder ruling that led to the jurisdictional issue was unreviewable as a collateral order.