Bolts snapped off from over torquing, especially small ones, are very easy to extract. Get some left-handed screw extractors and/or left-handed drill bits and it should zip right out.
BTW: common sense is thinking "this can't be legit" and then STOPPING and double-checking everything. A big mistake many home mechanics make is thinking that they can remember the torque ratings for every bolt (or even some bolts). A friend of mine who used to be an A&P mechanic suggests looking up the torque for every single bolt/bolt pattern right before you tighten them. It's the best way to make sure you don't screw up anything like that.
BTW: common sense is thinking "this can't be legit" and then STOPPING and double-checking everything. A big mistake many home mechanics make is thinking that they can remember the torque ratings for every bolt (or even some bolts). A friend of mine who used to be an A&P mechanic suggests looking up the torque for every single bolt/bolt pattern right before you tighten them. It's the best way to make sure you don't screw up anything like that.