JGroupsTransport.invokeRemotelyAsync() has a ResponseFilter parameter that was traditionally used only with ResponseMode.GET_FIRST, for remote get commands. In that particular case, returning a null when some of the nodes timed out and other nodes returned invalid responses (i.e. null) was acceptable.
ISPN-4979, JGroupsTransport.invokeRemotelyAsync() is also used by ClusterTopologyManagerImpl, with ResponseMode.GET_ALL. Here, however, returning a null instead of throwing a TimeoutException is not acceptable.