My boy has been ECed (to varying degrees) since 5 or 6 weeks old. At about 5 months he started pooping in the potty 90% of the time. He is now 15 months, and started walking about a month ago. Of course when he started walking we missed poops all the time. Not every time, but far more than the previous 10 months. After a few weeks now, I've gotten over it and just change the diaper and don't worry about it.
The thing I'm stressing about right now is that is doesn't seem to care or be aware of what is going on. My saddest moment was last week when I woke up in the middle of the night to a terrible smell. At first I thought I was dreaming, but then I rolled over and found him asleep....IN HIS OWN POOP!. He had a diaper on and it leaked all over the bed and him. It was total disaster and made me feel like all of our efforts were for naught. That said, we had a family round of the stomach flu and he was still recovering from that. But still, why would be sleep through that?
He has been going in the potty more now than the last few weeks, though we have misses every other day or so. I can't say that he isn't aware of what's going on when it is actually happening or even before, but he doesn't seem to care if he is in a wet or dirty diaper.
I just needed to grump a little, but I would appreciate any commiseration or advice.