What a great point! Never thought of this...
Maybe the mysterious "other person at Godric's Hollow THAT night" picked it up??
You're right though, how did they get the wand back to Voldy?? More, how did Voldemort get his wand back AND be able to use it the night he met and tortured Bertha Jorkins to death???! Even if it had been Petigrew who brought the wand back how did Voldemort hold it to use it (it was meant to take months of tender care just to get him SOME kind of corporeal life)??