What excuse does Hank give Carl for not accompanying him in Chapter Ten? How does he feel about it?

He calls Carl, saying that Amanda is throwing up and that he has to go home. When he tells Carl that he must go home, Carl expresses concern for the baby and offers to send help as well. Hank is touched by the concern and seems on the verge of warning Carl but thinks better of it and finishes by saying that Carl should be careful on the roads.