At the end of the day they are parents...they obviously didnt set out to cause their son any intentional harm...there's definitely no malice or even wrong doing in my opinion.
They had an 11 month old son who they just couldn't let go of and were clutching at straws, we can all sit here saying what they should've done or even what we would do but unless you've been through it you'll never know. Emotional stress etc can obviously influence decisions.
Someone said it earlier on in the thread but imo they just needed the extra time to grieve and come to terms with what they knew was gonna happ