Saving multiple assets in a single tab from BRM (Guvnor) throws "binaryUpToDate has been modified externally"

Issue

• If we try to save multiple rules opened in a single tab through BRM (i.e. Guvnor) it throws the error binaryUpToDate has been modified externally .

ERROR [RepositoryServiceServlet] Service method 'public abstract java.lang.String org.drools.guvnor.client.rpc.AssetService.checkinVersion(org.drools.guvnor.client.rpc.RuleAsset) throws com.google.gwt.user.client.rpc.SerializationException' threw an unexpected exception: org.drools.repository.RulesRepositoryException: Unable to checkin.
org.drools.repository.RulesRepositoryException: Unable to checkin.
at org.drools.repository.VersionableItem.checkin(VersionableItem.java:591)
at org.drools.guvnor.server.RepositoryAssetOperations.checkinVersion(RepositoryAssetOperations.java:141)
at org.drools.guvnor.server.RepositoryAssetService.checkinVersion(RepositoryAssetService.java:153)
...
Caused by: javax.jcr.InvalidItemStateException: Unable to update a stale item: item.save()
at org.apache.jackrabbit.core.ItemSaveOperation.perform(ItemSaveOperation.java:262)
at org.apache.jackrabbit.core.session.SessionState.perform(SessionState.java:200)
at org.apache.jackrabbit.core.ItemImpl.perform(ItemImpl.java:91)
at org.apache.jackrabbit.core.ItemImpl.save(ItemImpl.java:329)
...
Caused by: org.apache.jackrabbit.core.state.StaleItemStateException: da98caef-e1c4-4f98-880c-46a740c9131f/
{http://www.jboss.org/drools-repository/1.0}

binaryUpToDate has been modified externally
at org.apache.jackrabbit.core.state.SharedItemStateManager$Update.begin(SharedItemStateManager.java:663)
at org.apache.jackrabbit.core.state.SharedItemStateManager.beginUpdate(SharedItemStateManager.java:1458)
at org.apache.jackrabbit.core.state.SharedItemStateManager.update(SharedItemStateManager.java:1488)
...

After this strangely, we can still see the assets are getting properly updated in BRM (i.e. Guvnor). Why does the BRM complain this error?