I think it's just perceptual bias that's changing "how fast it looks". Just like how Phanza is thinking "looked a bit slow to me too" after you mentioned it, me saying that it's actually close to normal speed made you look twice.
Thing is, neither of us is used to chase camera. We won't know without asking Phanza.

BUT the point of my second post is that, having actually done an experiment with FRAPS - it is impossible to get half speed by "accident of FRAPS" - it would have to be set slow in the film viewer or afterwards in post-production. And once again, if that were so, then the camera angles would double in their speed of changing.
In other words, if it's slow, it could not be by accident. And from what Phanza said, apparently he did not intentionally set it slow.
Edit: Do fires burn slower at reduced speeds? Check out the F4U part. I'm not sure, as this could be a video card difference and I've never paid attention.