"I love the picture but I don't think the risk is worth it," shared one person in the comments.
Others were even less complimentary, branding the stunt "so crazy", "stupid" and "terrifying".
One person wrote: "While I dont wish harm on anyone. The ignorance these people display just calls for them to get hurt. Tempting fate is never a good idea..."
However the couple, originally from Louisianna, insisted they took precautions to make sure Castille was safe, and in fact Workman said it was her idea, not his.
"What is probably most surprising to any audience is that this photo was actually Kelly's idea," Workman told Business Insider.
"We are both in good shape, we know our bodies, and, in turn, we know our limits," he said. "We had faith in each other and trust to pull this off, and so we made the choice as a team to shoot it."
He added: "There is a lip where the ridge of the infinity pool juts out over the wall, where Kelly could get a solid grip and place her weight on her forearms. I held her the entire time, and, if zoomed, you can actually see my grip on her arm.
He also noted that the height is nothing new for the adventure-loving pair and also explained that there was another pool directly below, which made the stunt even safer.
"We have both jumped off of waterfalls and bridges much higher than this infinity pool, so the height aspect wasn't a concern for us at all."
As for who took the striking pic, Castille and Workman said that as with most of their images, they are done with a camera, a tripod and an intervalometer - simply setting the camera to fire every two seconds while they pose.
