He may be deliberately using a strange wording to point out that these activities "pass time" (and not much else). However, I agree that the wording is off. Especially considering that's what "pastime" means in the first place [1]. Paul Brians notes that "pastime" is correct, too [2].

[1]: http://en.wiktionary.org/wiki/pastime [2]: http://www.wsu.edu/~brians/errors/pasttime.html