This is interesting since RP uses the most common synthetic base stock (PAO) you see in the high quality oils...the same base stock German Castrol utilizes. The difference is in the add pack. Think about this for a minute - if RP contained additives that would cause a turbo to fail, would it not also cause other mechanical parts requiring lubrication on the motor to fail as well? I do think there are other PAO motor oils out there that are a better choice vs RP due to the add pack, but there is noting wrong with using RP. In fact, there are a number of guys that use it in the 7M, 1J, and 2J motors with great success...Supracentral is one of them in his MK IV and has posted a UOA in this section.
Kwan - the people that have these "stories" are clueless and are blaming an oil for something they did to the turbo, like inadequate oil flow or failure to provide a filtered (clean) oil source. Or, even more likely, the turbo was not assembled properly. This is speculation - I can tell you with 100% accuracy that the oil itself was not the cause on a properly built turbo with a properly sized/filtered oil source.