In how many hands has he not "done anything out of 
line?" Being that he's a relative 
unknown, you can't 
discount his doing this with AJ. He's most likely some recreational player (I'
m getting this from the fact that he doesn't have auto-
reload on).  Recreational players DO 3bet with AJ in the SB (along with other trouble hands).*
Also, please note his half-pot sizing on the 
turn and 
river. It's hard to really put him on a 
pair higher than your 
QQ. As I said earlier, it wouldn't be all to surprising if he held AJ or even a mid 
pocket pair.
Given that, I like shoving this 
river given it's most likely impossible for him to 
fold {AJ, 
TT-77} with what he's left 
behind. Sure, you may see 
JJ+ some percentage of the time...but it's hella weird given his 
line.
* - please 
don't take this to mean 3betting with AJ in the SB is never the correct play.