Reports or alerts or logs when Web Services into the CRM experience errors

Hello,

We have a vendor who has built custom forms leveraging the web services which come with Dynamics CRM.

However, there is no easy way to detect when those web services experience errors. The vendor, as of today, does not have a way of letting me run a report or be alerted when those errors occur. Though I can check the windows logs and SQL server logs for errors, the time of the errors on their custom forms never coincides with the time of the windows or sql server logs.

Is there a way I can build my own report or logs, and where can I check this information? Users often report errors on their forms hours after the problem may have occured.

Thanks