Accidental rebel - konstantin was wrongly assumed to be a rebel operative as he'd accidentally made friends with rebels during drunken pub crawls on coruscant, because of this he was labelled as a treasonous criminal, and because of this he was forced into the ranks of the rebels.
Konstantin was born on the dug homeworld of malastare in 26 bby
Crime - Konstantin used to be a racer, switching often between swoops and pod racing, he did this to escape his poverty as many dugs did under the oppression of the gran on malastare. But swoop racing and pod racing is illegal and a crime because of the empire. If the empire was destroyed then the new republic may free them if their gran oppression and so they'd make the racing legal again. Also treason against the empire.
0 duty - support - konstantin's main job also his best talent, to drive repulsorcraft, getting his allies into imperial controlled zones and then providing them a quick getaway, much like a getaway driver in a bank heist. He is also good providing support through the use of big guns, usually those mounted on ships because of his training as a gunner in the dug military