He collapsed in severe pain from what was diagnosed as badly-sprained right knee ligaments and needed medical treatment on the spot before he was carried away on a stretcher.
The start of the match was delayed by several minutes - and when it began Elgar played a loose shot and was caught behind down the leg side off the first ball of the match, delivered by James Anderson.
Kotze's his wife Catherine took over his ground level camera, while after treatment he hobbled up to a more comfortable position in the press box.
"I hope I didn't cause Dean Elgar to lose concentration," he said. "But when I was limping past some English guys they thanked me for the wicket."