SIL didn't ask a question so the OP doesn't even need to call back. The only way to handle PA comments is to take them literally.
POD. My mom told me a story today. Mom's friend, Linda's, has a MIL that hates her. MIL tells Linda and her husband, Don, the wrong time for holiday meals, telling the rest of the family another time. So when Linda and Don arrive (15-20 minutes before the time MIL told them) they find that the whole family has already eaten. MIL says, "Oh, the food was ready a little early, so we decided to eat without you." It's clear that the food is cold and has been sitting out for a while. Linda and Don are expected to piece together a plate from the leftovers. This has happened at almost every holiday since they got engaged four years ago.
So this year, Don asked his mom what time Thanksgiving will be held. He says, "Mom, please don't serve dinner early, before the time you've given me and Linda. It's upsetting for us to get there and find that you've already eaten." Mom huffed, "Well, if it's so upsetting, you shouldn't come at all." expecting Don to backpedal. Instead, he said, "OK, then." and hung up.
Cue dozens of (ignored) calls to Don's cell from MIL. And more calls from family members telling Don how much he had upset MIL by hanging up on her and telling her he wouldn't come to Thanksgiving. Don has been telling them, "Mom told me not to come. So I'm not coming."
Maybe MIL will refrain from PA comments from now on.
(Sorry for the threadjack.)