acyclically stereocontrolled reaction: organolithium and 2-chiral compound
I have just had a look at the paper and actually they reported that their main product was S,R: 

"...treated with excess 2-lithio-1,3-dithiane in THF at -50°C; this treatment generated the tertiary alcohols 22a and 22b in 72% combined yield with 6.2:1 diastereoselectivity as predicted by Cram's model based on participation of the piperidine nitrogen atom, giving a rigid cyclic complex with the lithium compound".

Compound 22a: (2S)-2-[(R)-l-(1,3-Dithian-2-yl)-l-hydroxyethyl]piperidine

Compound 22b: (2S)-2-[(S)-1-(1,3-Dithian-2-yl)-l-hydroxyethyl]piperidine

I do not find any mistake.