Southwest Airlines is the latest after canceling 2,000 flights over the weekend and hundreds more on Monday. The airline and its pilots’ association blame bad weather while the internet and Senator Ted Cruz have a weirder theory: pilots staged a sick-out over the airline’s new vaccine mandate.

Southwest Airlines rode through a turbulent weekend, Reuters. The carrier canceled more than 800 flights on Saturday and another 1,124 on Sunday, or 30 percent of the airline’s flights for the day. The mass cancelations continued into the week with an additional 588 cancelations on Monday and about a hundred as of this morning. Travelers piled up at airports having to find a new way to their destinations.

The airline and its pilots’ union blame bad weather and air traffic issues in Florida for the cancelations.

If this sounds familiar, it’s because both canceled over a thousand flights earlier in the year. Spirit’s cancelations were so bad that it . Why would this be any different?

The cancelations came only days after the (SWAPA), a union representing over 9,000 pilots, asked a court to delay the airline from carrying out a COVID-19 vaccination mandate, Bloomberg. The pilot union alleges that the airline violated the Railway Labor Act (a statute that also governs airline unions) in imposing the vaccine mandate on its pilots. The union believes that even COVID-19-related changes to its collective bargaining agreement require negotiation.

SWAPA that it is not against vaccinations and in fact, the union against passengers who don’t wear masks. But Southwest Airlines imposed the mandate without consultation with the union about exemptions or terms.

Naturally, the internet, along with Texas Senator Ted Cruz and Donald Trump Jr., began spreading speculation that the cancelations were caused by pilots staging a “sick out” as a form of protest.

Some of the speculation appears to be driven by the fact that other airlines didn’t have nearly the same number of cancelations as Southwest. But that’s exactly how it happened earlier this year when American and Spirit canceled and delayed thousands of flights while other airlines didn’t have issues.

As by the Dallas Morning News, Southwest typically runs 40 percent to 50 percent of its entire fleet through Florida. So a disruption in Florida, such as bad weather, can cause chaos in the airline’s schedule.

SWAPA union president Casey Murray confirms what the airline says, the Dallas Morning News:

While there have been employee protests over mandates, pilots union president Casey Murray said there was no effort by pilots to disrupt Southwest’s operations.

“We have the data from this weekend and our sick rates were exactly in line with where they were all summer with the same kind of operational disasters,” Murray said.

The airline struggled to recover from its initial cancelations over the weekend. Pilots and flight attendants had trips rearranged to cover for cancelations. Some crew members hit their maximum working hours, forcing them to get rest while the airline found others that could fly. Incoming Southwest CEO Bob Jordan described the situation as planes and crews being in unexpected places.

The Federal Aviation Administration backed both the SWAPA union and the airline up:

So if your Southwest Airlines flight got delayed or canceled, don’t blame flight crews. Southwest’s flights were delayed by bad weather and planes being in the wrong place at the wrong time, not by a protest.