I would be surprised if this safety trial were randomized with respect to the CRISPR manipulation. I agree with your assessment of needing more data to believe that the gene editing manipulation was successful.

I suspect the randomization relates to the allocation to the experimental arms as described on the reporting page:

    This is a dose-escalation study of ex-vivo knocked-out, 
    expanded, and selected PD-1 knockout-T cells from 
    autologous origin. Patients are assigned to 1 of 3  
    treatment groups to determine the maximal tolerant dose