Unfortunately, the field of discipline gives many teachers, parents, administrators, principals, and regulators stomach aches. The discipline rules have become fairly complex. When understood in context, however, they are not so hard to apply.
The new OSEP guidance includes OSEP's take on whether disciplinary rules apply when the parent revokes consent for services tat had been being received; that home instruction cannot be the sole IAES option; and clarification regarding the behavior requirements. You can review the new policy guidance here.