Can someone assigned the Teacher role change attendance for a class he/she is not assigned to as a teacher? That appears to be what I am seeing.
Yep, that’s the idea. 
No way to set boundaries? I don’t want other teachers intruding into my class(es) to take attendance, whether on purpose or by accident.
Hi Tieku, the system works this way by default to allow teachers to cover other teachers classes. Eventually someone gets sick or takes time off and you’d need a way to allow other staff to take attendance for your class. Every attendance record includes the name of who took it, which should help.