It is infrared, but I don't think film was used. Probably used a digital camera that has been converted for infrared use. After all, why say "no photoshop was used" instead of "this is XXX film".
One of the other infrared photos in that photostream has a bit of colour in the sky, which wouldn't happen with film. And some of the images are in shade, but with a strong infrared effect, which would indicate a longish exposure, from which I would expect a little movement from the people, but they are pretty sharp. I'd also expect grain with infrared photos taken on film.