Can I ask why your surgeon took a different approach for each breast? Was this a reconstructive procedure
I am also concerned with the tugging of the skin you described. With plastic surgery, it's generally best to not touch the incisions (except for cleaning) until they heal.
As you stated, it very well could be dying or damaged tissue (but without the other nipple to compare it to, it's difficult to say). Your plastic surgeon should be able to provide a clear answer. What did he say during your appointment?