I'm sorry your wife is going through that, it sounds really uncomfortable and stressful.
For sure it's correlation and not causation, however, it certainly is not impossible that his wife's body could have that sort of reaction. I'd be shocked if there were not tons of weird one-off reactions to any vaccine or drug, or food, or whatever. We're huge sacks of chemicals all slightly different that will have slightly different reactions when other sacks of chemicals are introduced.