Improper service. Failure to check a particular box. Leaving the record blank. For a sense of all the various procedural things that can go wrong in a deporatation case, here you go.
I think that Judge Berzon is right to be a stickler here. We generally shouldn't deport someone in absentia and with no real evidence produced against him unless there's a darn good reason to do so. Which there isn't here.