It's not a case of stretching the contacts per se.. the contacts that touch the jack plug seem secure enough.. if you look
*HERE*
you'll see in the upper left that the headphone jack isn't attached to the board, but the case.. and in the lower right (look for the orange rectangle near the sd card) is the board it presses against.
For some reason Motorola thought not soldering the two pieces, but merely relying on contact via sprung pins, would be a better idea.
Mine failed after a month or so, became horribly scratchy and would cut out or skip songs with no movement. I got a refurb and have used bluetooth exclusively since then. No more jack issues