A timeout room is used on rare occasions when a student with a disability is a danger to himself/herself or others. It is used as a last resort and is never used as a form of punishment.
From Time-out Procedure provided in 2008:
A student is placed in the time out room contingent upon severely disruptive, out of control behavior.
These are two of the seclusion room incident reports that I was given once I knew to ask for them (names of staff removed for privacy).
Used as a last resort when the child was out of control and a significant threat to others? You be the judge...the child was in kindergarten at the time.