Well, yes, but he's just recovered from being shot and nearly dead. He shouldn't be wandering anywhere. It is not the first time he's gone missing or without supervision, though.
But, rather than blaming Carl (who is a kid after all), his parents don't seem to be doing a very good job.
Also, I forgot he showed up limping and muddy and out of breath, and his mother didn't think to question any of those things at all.
Yeah - I thought about that, too. Maybe she just thought it was a boy being a boy and getting muddy & dirty from playing/jumping around.
However, she has been pretty overprotective of him throughout - yet no questions?