Acting is different than actual though, in practice. 9/10, acting officials are career feds, who, to avoid the legal uncertainties of appointee vacancy requirements and restrictions, rock the boat as little as possible. This is generally fine for obscure, deputy level officials, but the IG office in particular needs to have someone who can rock the boat, and stand up to senior agency officials, and if necessary, be the canary in the coal mine and take the bullet to bring a major issue to the attention of congress. Senate appointees know their tenure is limited. They haven't planned their career around the federal retirement age like an acting Civil servant has.

I agree that the article could be clarified, but its important not to treat acting officials as the same as appointed officials when in practice they aren't.