I firmly believe in this very section he's trying to explain things using decontextualized examples.
The two examples where intransitive "open" appears in Swan are provided under sections 493 (item 9) and 609:
I have to say I don't like the examples under item (9) above, where it says Some other verbs which do not normally have reflexive pronouns... While it is true that those verbs will not take the reflexive form, it is also true that speakers and students of English will not readily understand why verbs like concentrate, feel and hurry should be reflexive at all.
Section 609 is, in my opinion, clearer and fully in line with David's explanation: inanimate subjects (i.e. things) cannot engage in voluntary actions and take reflexive verbs. Excellent examples of verbs that don't take the reflexive form when used to refer to things in subject position are start and move (see above). Other examples are the verbs break and close.