What we see on tv is not what a fighter feels in combat, I'm not saying Chael was right but he wouldn't say that unless he felt something.
That something was probably Silva just holding on and not being offensive or not even trying to get Chael off him.
Maybe Silva felt like he had more resistance until Chael landed that elbow, afterwhich maybe Silva just went into defensive hold on mode.
In any case, what Chael said is essentially right - Silva was under Chael for 4.5 rounds last fight, and the whole of the first round. Intentional or not, Silva has unbelievable mental strength to come out that second round and finish Chael at the first opportunity that presented itself, hands down and all.
I've just rewatched the first round again for that issue. Silva started to clench on Sonnen the moment they hit the floor (and thereby controlling his posture). The elbow doesn't make any difference in his behaviour (it isn't a hard strike anyways), but with the first fight in mind, where Silva fought back from his back with strikes, I can see Sonnen missinterpreting Silva's behaviour. While Silva is just clenching to him, controlling his posture and making his opponent wasting energy, Sonnen thinks that he has broken him mentally as he doesn't strike back like in the first fight. I don't know if that was planned by Silva, but the confusion in the second round of him comming strong and being able to stuff the TD attemps certainly played to his favour.