Hank Green - Phineas Gage chords

Not sure if these are 100% correct, but i was watching Hank play and it looked and 
sounded like this was what he was playing. 
Standard tuning
[ Tab from: http://www.guitaretab.com/h/hank-green/286994.html ]
D                    C              G
Oh, Phineas Gage was 25 years old in 1848.
D                     C                        G
And he liked his job, working at the railroad, but he had another fate.
D                                           C
He was blasting rock when something distracted him.
D                              C
And he forgot to put the tamping sand in.
D                         C                     G
He shoved the tamping rod into that little hole onto the blasting powder.
D                   C                                    G
And suddenly his entire left frontal lobe had been turned into clam chowder.


D       C       G                      D     C     G
Oh this is the story of Phineas Gage, who was stabbed in the brain.
D       C       G                      D     C     G
And once your frontal lobe has been destroyed, you can never go home again.

And so on. DFTBA