With Thiem leading 3-1 in the second, at 15-15, one Goffin return was called out. Goffin correctly challenged it. The umpire determined to replay the point. Thiem acknowledged that the call was made after he made contact with the ball in his response, which went out, thus conceding the point. It was in a very tense moment of the match, just after an 14 minutes game in which he had a lot of chances to go up two breaks. That's sportsmanship.