SPOILERS FROM SEASON 8 MID SEASON FINALEPaul,
He DID get bitten when he was in the woods and found the guy Rick had shot at (a warning shot) Walkers attacked him then.I believe it was last week's episode.
As far as surviving, I really wish he could, but since the bite is on the stomach and not on a limb that can be amputated, I don't see how. If he did surive, IMO it'd be something like Glen under the trash dumpster (jumping the shark a bit). Then too, poor Carl is already missing an eye, can't have him miss a limb too.
When episode started with Carl writing note to his dad, I thought he was contemplating suicide and thought "no that's doesn't sound like Carl. When he confronted Negan telling him to shoot him, Carl knew he had nothing to lose and wanted to end the turmoil.
We, the audience, didn't know until the very last scene as Rick entered the sewer. That long walk toward his son, with everyone kind of looking away, we just KNEW something happened. I love these episodes, even if sad, it's those kinds of surprises/plots that really get you.
Here's video of of when Carl got bitten.
https://youtu.be/PfZcH0GmT1w TIS
