The problem with that is that John warned her ahead of time that he didn't like crowds at least twice only to have her ignore his feeble attempts to sway her in the name of her being a party planner extraordinaire. In her mind, putting him in a social setting he felt uncomfortable with would magically make him not horribly self-conscious; that being said, she should also have noticed that compared to her, he's a lightweight. She can hold her liquor while he's more or less down for the count as soon as he sniffs the bloody cork. When you realize that she ignored his warning her because she'd rather not hear him and failed to remember that mouthwash would leave him staggering, this upcoming mess is at least partway her fault for tempting fate.
The problem, of course, is that this is symptomatic of a larger problem: Elly's refusal to heed any sort of warnings that might require her to reconsider an idea she's got stuck in her head. Another example of this is, of course, her insistence on not listening to flood warnings during the early spring of 1995; in her mind, you see, a child will ALWAYS sit quietly where ever Mommy plops her down so she never actually had to worry about where April was. Any sort of suggestion that April had to be watched over or that children aren't grinning little dummies content to sit and stare quietly into space were immediately rejected so, well, it's not as if it were her fault, right?