All patients in the trial received chemo-radiation and then follow up chemo. psPD is known to happen up to 3 months or so after the end of the chemo-radiation.
The trial randomized into the trial a few weeks after then end if chemo-radiation. So all arms will show psPD based on that.
It is true that DCVax-L almost certainly caused additional psPD. But that does not mean other cases were not present without it.