Rcvf in cl

I have a coworker that is reading an LF in a CL as a driver. The LF has a
select of "processed <> 'Y'". Her CL calls an RPG program. There are
multiple records with the same key so the RPG program processes all of them
and marks them all processed ='Y'. When the RPG exits, it loops back up to
the rcvf to get the next processed <> 'Y' record. However, when it does
the rcvf, it is picking up records that were just updated by the RPG so
processed = 'Y'.

I have reviewed the code and found nothing unusual that would explain
this. No opnqryf, cpyf, etc. It is just a read loop with the call to the
RPG and a few miscellaneous file locking commands in between.

Does CL take a snapshot of the file before it starts reading or why would
it read records that should be excluded from the LF?