I had a first grade teacher who tried to do this last year. I told her she
could not use specials as a punishment as they are part of the curriculum just
like math or science. (I did tell her this in a nice, very quiet way) She is
young and got upset about how it made her look so I told her to take the child
and send him back when he had finished his work.
She came back to pick up the kids and appologized and said she did not
realize when she did it that it was the wrong way to discipline the student. Now
she does. It was handled very professionally.
The flip side is that I had a student who just wasn't working and I wanted to
keep him and have him finish his work. I called the classroom teacher, told
her the situation. Her response was that while she would have liked for me to
keep him, he had math next and he really needed math!!! (which I completely
agree with) So I had him come in and make up the time at recess...which is
what I usually do anyway!
I hope this helps. Many times, (sad but true) specials are viewed as "extra
treats". So when I explained my position to the teacher in the story above in
a nice way with a solution that let her "keep her authority" but also
educated her, we both won!