Originally Posted by Diesel911

With good luck he will have enough sticking out to unscrew what is left.

What I have found that is extremely important when using Ezee-Outs is drilling the hole in the center of the Bolt/Stud and using the correct sized drill to match the Ezee-Out you are using. (Center Punch the hole before drilling and if you have thinner drill bits; drill a piolet hole with the thinner drill first.)
As stated by the time you drill the hole with a Left Handed Drill Bit the torque and heat created by the drilling will often loosen it and even spin it out.
Also the Ezee-outs that have a spiral or screw like appearance can expand a hard to turn out bolt.
(I have not used the newer self drilling types so I do not know how well they work)
Here is a pic of some spiral and some square Ezee-Outs.