Let´s bring some more usefull information to this thread.
A while ago I shorted 3 of my motors because the mounting screws where 1mm too.
Due to vibrations the screws rub off the isolation and than shorted the phase wires to each other via the motor case.
Here is the way how I fixed it and double checked that everything works without issues.
I measured the resistance from the mounting hole to the phase wires like this
That gave me 0 ohms, so a full short.
I thought I can easy fix it by just adding a piece of heat shrink over the wires, but there is no way to get it there without to take off the top part of the stator. As this part is usually glued in it’s pretty much not possible without proper tools.
(Or as min not for me as noob 
)
I first tried to cover the damaged part of the wire with liquid tape, what worked out, but I wasn’t super happy with it.
I decided to make that thing bullet proof by epoxy the phase wires all over the place where they where damaged.
That looked now way much better, but the question was,
how to double check if really all damaged parts of the isolation now covered?
Sure you can just spin it up with your ESC but with it you risk to fry one more controller.
So how to do it without? 
Our outrunner produce a specific current and voltage when spinning (regenerativ breaks), so if all phase wires are ok, than the voltage produced while spinning should be the same for all three wires, right?
Right, and here is the most easy way to check that.
You need your motor on the motor mount
You need a drill
And you need a multimeter set to AC voltage
Connect your multimeter first to phase A and B
Than connect the drill to your motor shaft
Spinn up the motor with the drill
Check the voltage on your multimeter and remember what was displayed
Than move on and connect the multimeter to phase A and C
Spinn up the motor again
The voltage reading should be the same now
If yes move on and connect your multimeter to
Phase B and C
Same test, same result.
If in all three cases the indicated voltage is the same, you good to go and can use your motor like before.
Dissclaimer: I know there are other methodes to check if the phase wires have a short, like the hand test as well as the easy way to check just the resistance of the phase wires. What I hope do detect with this variant is a “light” short, means it´s not a permanent short. Maybe there is still a small gap between the shorted points, or the short only show up in time of rotation, or due to vibration.