There is no condition - other than when installing new Cocoa 
behaviours or changing a preference setting - where Remote Buddy 
would quit itself (but even in those cases, it would automatically 
relaunch). So if no logfile exists in that directory, that really 
leaves me with no idea of what could happen on your Mac.

However, it's not unlikely Remote Buddy crashed on your Mac for the 
same reasons that it did on Andreas'. Please download and install the 
latest version and let me know, if the problem persists.