Doc changes the TARDIS lightbulb in Pond Life. I'm trying to remember if they flickered in the prequel to Asylum.
I just get the impression that there is a lot we're supposed to infer from these episodes without having a whole lot of information to go on.
I think you may be right. Under Moffat sometimes I feel the dramatic beats are sometimes erratic, sometimes they're missing when you'd expect them and sometimes they seem to pop up unannounced.