Will Limited Sun Exposure Before Ultherapy Cause Welts and Swelling or is It More Likely Due to Incorrect Depth of Procedure??

I had full face Ultherapy performed on 7/31. During the procedure, the Dr. commented on how red my face was starting to become and decided he would not complete the "2nd portion" of the procedure as he was concerned about "blistering". He rescheduled me to return for remainder of the treatment 6 days later. He and his nurse insisted that this "reaction" was not common and repeatedly blamed this on my recent exposure to the sun. ( I was not sunburnt but had been outside for up to an hour two days before the procedure...but again, I was not red at all.) Well...as soon as I arrived home, I noticed welts appearing on both sides of my lower cheeks and a hard nodule by my right eye. The next morning, my face was incredibly swollen, welts, persisted and I noticed a loss of sensation to lower jaw area. This has continued into the 2nd morning so I called my plastic surgeon. According to the nurse, I am to place cold compresses and 1% hydrocortisone cream to affected areas. Again, she blamed the reaction to my sun exposure. Is this true or more likely due to incorrect depth of procedure?