However, they're right, and I'm wrong. Apparently, when you're off work due to an injury sustained in the workplace, you are paid for every day you're out of the office, including weekend days.
The kicker is that you're not paid every single day unless you've been out for fourteen days or longer. I was out thirteen days - one holiday, four weekend days, and eight work days - so thanks to some magic Washington state formula, I get three days' pay subtracted.
Damn it! If only I'd stayed away from work for one more day, I would have been paid sixteen days' benefits, instead of only ten.