45F, scar on neck after deep plane neck and facelift, was I just unlucky? (Photos)

It appears that you developed either a pressure ulcer or ischemia following the deep plane facelift. It may have been due to dissection too close to the skin and not leaving the skin flap thick enough, or perhaps a tight pressure dressing applied following the procedure. The other issue is the immediate postoperative appearance of the submental incision which appears to be infected and the neck may have succumbed to the same infection. Either way, the scar you now have can be managed conservatively with steroid injections for now. Further intervention would be determined based on the the response to the steroids and time.

Yes, unfortunately those with thinner skin are at a slightly higher risk of having skin issues after a facelift, Fortunately, the area you show has healed beautifully considering its starting point. Another option to address that scar bad would be to excise it and perform a Z-plasty.