Id have probably came in for a raise even in EP with a2 and 2 random high cards.
It thins the field a little and defines your hand.
The way its played its marginal , if the shorter stack was the one potting all in id call and the bigger stack may be reluctant to bet you out of a dry pot and let it go to showdown and you hopefully get at least the $4 split. The fact its the bigger stack who initiated the betting and potted the flop , its very likely he will pot the turn and with no high and just the low and only invested for 0.70 its a fold imo.
I know youd have hit the wheel but thats irrelevant it doesnt really matter how it panned out just what the long term +ev play is and id say its a fold.
The shorter stack could have absolutely anything but you have to give the bigger stack credit for something or other here as he probably realises the shorter stack is calling super wide but hes potted anyway.
So yeah id say fold and raise the a2 with 2 high cards preflop most of the time
Unlucky the way it played out though but calling would have likely meant simply drawing to get your $$ back with little scoop potential.