Tried it three times now.
Stole the painting the second time and checked my inventory to make sure I did indeed have it.
Went back to Sabrina, no painting in my inventory.
Secondary issue, I thought we were supposed to get Eldevin points for playing Beta? I didn't get any. Did that get cancelled or am I overlooking something?
I'm off to try the Study in Blood one more time before I move on to another quest.