I haven't run the procs as described in the article but the most troubling error handling I've had to deal with are errors like PK violations that abrubtly halt the entire batch that was sent by the client, in this case no matter how far you've nested the procs, the entire process is aborted and an error returned to the client, I would like to figure out how to trap these kinds of errors in TSQL and deal with them before my procs return control. For other ways of dealing with errors, see the master database and the SQL Server's own sp_ procs.