While the timing was odd, the short positions against major airlines were actually fairly logical trades. The economy was slowing and when that happens, people take less vacations. There were also huge shorts taken against airlines recently, and I doubt there's a terrorist attack coming. Shorting airline stocks is a high risk bet on consumer confidence declining - these companies are always on a knife edge for profits, where a lower passenger count can turn the entire business over, like Spirit Airlines recently.

I'd also say that this trade was likely a bet on a disliked VP over anything nefarious. In case everyone forgot, Trump was widely predicted to announce his VP shortlist at Butler.