FL,
That's the best question of all. Had it been the right 757, photoshoot accomplished and separation re-established, would anyone have been the wiser until - perhaps - weeks later? And then? A formal wrist-slap, some very suppressed grins and a deniable rumour? What a temptation it must have been and one wonders, how many readers of this thread have done the same or similar and now thought "there but for the grace etc."
This is not to belittle the dangers of heavy aircraft flying close to each other. My own background is marine where we have a history of gruesome accidents caused by enthusiasm overcoming caution. Nothing's ever heard of the cases where an up-close photo of "me on my final voyage" wasn't accompanied by a scrape.