It does not appear that Larry's father foreswore liquor, even after the tragic and embarrassing incident at the bar with his young son. He does seem to realize, at least for the moment, the devastating effect his drinking is having on his own life, that of his family, and, in particular, his son, saying,
"Never again, never again, not if I lived to be a thousand,"
but the author communicates the sense that his resolve is not long-lasting. Although Larry's father goes to work in a subdued manner the next day, and his mother, with renewed hope, tells Larry that he has proved to be his father's "guardian angel," Larry concludes his account of the situation by saying,
"To this day, I don't know whether he was foreswearing me or the drink."
This statement indicates that the result of Larry's father's foreswearing was not clear; had he truly and effectively foresworn drinking, Larry would have known what the object of his foreswearing was. As it is, Larry does not know for sure what his father meant, leaving the impression that though his father improved his behavior temporarily, the effect of being so shamed by the incident with his young son did not last.