Correct. It still applies. However, the distinction is that Singletary is not really the HC, but only an interim HC. Therefore, the Rooney rule applies to them hiring a new coach. As someone else pointed out, ask Haslett.
And I don't think what San Fran is doing is right. It is true, Singletary is black and the Rooney rule is supposed to lead to more black coaches. However, most proponents of the Rooney Rule would say that is does more than this. It offers interviewing "practice" for black candidates and allow them to get their name out there and "network" with NFL people. This is the problem; by just handing Singletary the job, it actually hurts other black candidates in the process.