Complex sentence: During the third match he scored 19 before he was stumped by Zulqarnain Haider it turned out to be a mistake by the umpire as he had pressed the wrong button.
Split into simpler sentences: During the third match he scored 19 before he was stumped by Zulqarnain Haider. It turned out to be a mistake by the umpire as he had pressed the wrong button.