Not sure if this happens to anyone else but occasionally I can instantly repair both wall turrets and vehicles with a single tick of the glue gun, I never could figure out how to reproduce but it definitely happens. In fact it would explain a lot of "shifty" things I've considered as being hacks. I remember strafing a Sunderer in a Mosquito and getting it on fire, then as I reloaded my M18 Rotary it instantly went to full health. Probably the same bug tbh.
Not gonna lie, when I'm trying to rep a gen in a highly contested area I pray for this bug. Someday they'll fix it, in the meantime just put in a bug report when it happens.
I hope its a feature for when you capture a base, because spending that time repairing every generator is insane.
This bug has existed for a long time and still happens, It's completely unbelievable this has not been addressed yet.
I wouldn't mind if it happened in spheres of influence with zero enemy activity for turrets/generators but vehicles is lame as the downtime to repair/rearm is a consideration to make when farming certs. I also don't think it's beneficial or intended to happen while being fired upon, like I said, got a Sunderer to flaming, probably a tenth of his HP left and it instantly went to full green. It was pretty infuriating at the time.