Chelsea manager Thomas Tuchel blamed the floodlights for Manchester United's goal at Stamford Bridge on Sunday.
Jadon Sancho fired United ahead five minutes after half-time.
The English winger dispossessed Jorginho and raced clear before slotting past Edouard Mendy.
But Tuchel refused to blame the Italy international, saying: "He misjudged the situation and I think he was heavily disturbed from the lights. It happens."
Jorginho made up for his mistake by converting from the penalty spot to tie the scores at 1-1.
Tuchel added: "It takes a lot of courage and personality to not be affected during the match and to have the courage to take the penalty. I am very happy that he did it."