Shocking scoring error helps knock Venus Williams out of Wimbledon

I had Wimbledon on in the background just now, and Venus Williams lost to Karolina Sprem 7-6 7-6. The shocking thing is that in the second set tiebreaker the chair umpire made a scoring error, calling it 2-2 when it was actually 3-1 in favor of Venus Williams. The players didn't say anything and kept playing, and Venus went up 6-3 and should have won the tiebreaker (the score should have been 7-2). Instead, Sprem came back and won.