sanctuary or not ?

[btdt]

R-1, R-2 No out
Fly ball to deep center caught by F-8
R-1 tags and advances to 2nd
R-2 fails to tag up and is slow in returning to 2nd
Ball comes into F-6 covering 2nd
F-6 tags R-1 and then steps on 2nd for the appeal play
Is this a double play?
or
Does R-1 have sanctuary on 2nd even though the base still belongs to R-2?

Can't figure out which rule would cover this.