It apears that the issue is not fixed yet. You can vote for it, or track it's progress on our PITS system. It is named (Expander: Expand-Collapse animation) and will be available not later than 24h from now.
Sorry for any inconvenience.
All the best,
the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items