Answers
Jake was stunned for a brief moment by the bomb that the old alien had just dropped, but he recovered immediately. There wasn't much left to surprise him after all he had endured in that Ordeal.
Treading on an asteroid? Check. Being eaten alive multiple times? Check. Drowning? Check. Camping in the magma chamber of a volcano ? Check. Exterminate a tribe of man-eating aliens? Check...
Meet their primordial god or ancestor? At this point, he had already become insensitive. His amazement came simply from the fact that it was unexpected for him that this alien had taken the trouble to save him. After all, Jake had exterminated an entire tribe of his descendants. In contrast, the fact that such an individual knew his name was not so strange.