When J was nap-dropping, any time she had a smidgen of sleep during the day, bedtime ALWAYS ended up being later. She just couldn't sleep, even after a 5minute power nap on the way home from the grocery store. and Heaven help us if the nap was late in the day.
It sounds like he might be getting a second wind. Any chance of putting him to bed before he gets wound up again? Or keeping the evening super-low-key? Our rule for a long time was that after 6PM/after supper things were to be low-key: no wrestling with Daddy (took DH a while to get that one and then I let him put J to bed after those and he FINALLY got the idea that winding her up didn't work *facepalm*), no running around, quiet volume. Even now I try to get the girls to keep from getting a second wind if I want any hope of some Me time in the evenings. The massage at bedtime really seems to help, as does some quiet music to help set the mood.