Btw, he already answered his own question in the first place: (i know it will very from batch to batch, burner to burner)
It will, with burner, speed, firmware, batch, media, scanning speed, scanning drive, tiny specs of dust plus MANY more variables. Any of those could have caused the small increase of PIF. Maybe his liteon was having a bad day and felt like scanning with a few more PIF at the end.
Is it so wrong for me to suggest he is reading into the scans too seriously? Honestly, is it?