When i tried replacing a receptacle, I first found the wires sticking out of the back holes, not completely insulated. As in, insulation was stripped 1 cm too much. So I did the same thinking its the way its supposed to be. Is it imperative I redo it and cut the wire to the proper length so the insulation can go into the hole?
When using back stabs it is important to use the strip gauge on the back of the outlet. When properly stripped the insulation is slightly supported by the device. If the copper is exposed the wires tend to break at the strip point even if the wire did not get nicked. If the wire was nicked when stripping it can break much sooner without support. With the power off there are usually small slots that another 14 gauge solid wire or a small screwdriver can be used to release the wire trim to the correct length and reinstall.