Configuration of chiral center in cocaine
You are actually right, that stereocenter does have R stereochemistry. The four substituents to the chiral center in question are:


1 - $\ce{CO(O)}$ = $\ce{C(O)3}$
2 - $\ce{C(O)(C)(H)}$
3 - $\ce{C(N)(C)(H)}$
4 - $\ce{H}$


These are ranked and numbered according to the Cahn-Ingold-Prelog priority rules. Adding the numbering to the structure:



Orienting the lowest priority group away from us and following the direction of the numbering, we confirm that it does indeed have R stereochemistry: