Minor Description
If the last remote service of a type and version is de-registered from the cluster it remains registered on the local OSGi service registry. The consumer then calls the proxy registered by DOSGi on the local registry and gets a timeout after the default 30 seconds.
In order to make it fail faster I would propose to remove the proxy registration from the local service registry to get a OSGi service not found exception right away. This also prevents memory overflowing with waiting calls and the consumer can do better the transaction handling.