Kent Said:

I can't believe they didn't teach!?

We Answered:

I was a math teacher for 34 years and I never had much expectation about would be taught when I was out. If nothing was broken in the room when I returned, I was satisfied. I wouldn't make a big deal out of this, unless you are on good terms with the principal and mention it in passing. It may cause more ill will among your colleagues than it is worth. You can be assured that it will get back to all the teachers involved.
It is a pain when one teacher has to sub for another, giving up a prep period or something they were planning to do.
Whenever I had either small or large "flaps" with fellow teachers, I always regretted my behavior.
One great thing about teaching is that every day and year, you can start over fresh and erase the missteps of the past.
Make a calendar of the number of days you have left, and X them out every night. It helps.