Benefits Administration - Ids not deleted from BAS Activity table

The BEN Admin ran to error the 1st time with an Array size issue (Max no.of Calendar rows exceeded). When re-ran the process, it went to success and the events got created for all the employees in BAS Activity table. However some of the employee ids (not the entire list) did not get deleted from BAS Activity table. Any reason why ?

When I compared the count between BAS activity and BAS Partic for the event date and event class, it matches accurately. Hence the event class got created for all without any issues. But would like to understand why the BAS activity did not get deleted for some ids.