I think this is behavior by design, without knowing it for sure.
Alexander from the Telerik Team showed me another implementation instead of using the way of passing in XML. You can see his solution here
. Maybe you can try it out, I haven't got the time do so yet.
However, it seems like the Database.Get(....) call is caching the connection information for the respective connection ids. Maybe a solution would be to provide different connection ids in the Database.Get(...) calls.
Hope I did point you in the right direction.