This behavior is indeed logged in our system as a bug
. Currently, we are monitoring our customers' demand. Fixing this particular bug is with low priority because you can achieve multiple selection logic on application level using binding to the RadTreeViewItem.IsSelected property and controlling the selection through code.
Pavel R. Pavlov
Check out Telerik Analytics, the service which allows developers to discover app usage patterns, analyze user data, log exceptions, solve problems and profile application performance at run time. Watch the videos
and start improving your app based on facts, not hunches.