Yes, I understand this. I quess my confusion in this subject arises from the definition of photon (E=hf), which tells me that even if you stretch a photon, it's energy remains the same and therefore there should be no change in frequency either. But same time I also know that peculiar motion causes redshift by a similar mechanism as in space expansion, this tells me that if space expands it really should cause redshifting.

After thinking about this for a while I think that my confusion cannot be solved until we know what photon really is. So I'm going to steer my thoughts back to earth now and conclude that photon is quite strange beast.