Bill Viola photobombs in pioneer performance

Could this be the first ever example of artistic photobombing? The year was 1975 and the young man in the wide-lapelled coat is the US artist Bill Viola. The image documents his performance Free Global Distribution (Surrogate Broadcast TV System), in which the artist tried to secretly stand in as many tourists photographs as possible in one day on the streets of Florence, in this case in front of the Duomo.
Viola was working in Florence at the video production studio Art/Tapes/22, and the title