PROSECUTOR COMMENTS ON DEFENDANT'S RIGHT TO REMAIN SILENT, RECKLESS OR INTENTIONAL??

In a captial murder trial the State prosecutor commented on the Defendant 5th Amendment rights. The Judge declared a mistrial. Federal Double Jeopardy law says no new trial for the State if it can be shown that the prosecutor's conduct was reckless or intentional. Tim Cole, the district attorney for Montague, Clay and Archer counties argued that the prosecutor's comments were due to inexperience and were not intentional or reckless. The Fort Worth Court of Appeals went with that explanation.

Does it make sense that a prosecutor trying a multiple count captial murder case isn't experienced enough to understand how the 5th Amendment works?