"You can never get fired for following the methods and doing your job."
Well, from years as a steward I would say that is naive although doing both gives you a better chance of getting your job back.
"I thought that all drivers elected the Teamsters to represent them?"
No, many are not even Teamsters and many that are never voted a day in their lives .
"just a coincidence" nope, probably not, although possible.
It could have been one heard a fed up tired driver say Thursday morning or night that they had had enough and were going to call in sick and the rest just thought that was a great idea not realizing so many others thought so too.
Quite possible with a seriously overworked workforce.
More likely there was some discussion though and that would be very dangerous for those involved.
If they were purposefully involved in an organized unauthorized work stoppage they would be subject to discipline up to and including termination.
Naive challenges like "prove it" are equally dangerous.
I would be very careful about talking about this incident if I was a driver involved as from a practical standpoint you could personally convince UPS to make an example of you and in the large picture 18 drivers nationwide is a disposable group.
UPS could decide to fire these drivers and unfortunately the burden of proof would be on the drivers, not the company.
Yeah, I know, that ain't right or democratic, but guess what, work ain't.
They trump up 17i (all other serious offenses) or whatever it is in your area which negates "innocent until proven guilty" and then you have to use the grievance procedure to get back to work.
The company could go hard ss (naw, they never do that) and force this up the line.
Several weeks or months later you are facing an offer of getting your job back with no back pay or gambling it all for the same or perhaps UPS decides to really send the message and your only chance is the union backs you all the way to an arbitrator and you win, something, even there perhaps only your job back without pay, except now you've been off for over a year.
Who knows.
I don't know anyone that really wants to put themselves in that position voluntarily.