How to enforce single execution of TCER at a time in RQM?

 We have a problem where testers have an existing "In Progress" result for a TCER which they have not completed.  When they go back to that TCER, they click "Run" instead of "Resume Execution" so that they now have two "In Progress" results.  Is there any way to prevent this?  I could not find any pre-conditions for that.  We want testers to complete an execution before they create a new one.  Otherwise, it causes problems with our reporting.