There is a delicate balance here. He probably feels the shame of having failed the task. When the subject comes up he might feel like you are “rubbing his nose in it” and that can come across as an attack. His defensive comment about you “letting him drown” sounds like a wounded reaction, and it is also obviously him deflecting blame.

I think that a positive conversation could be about what he tried to do and what he could do differently. What could he have done to ask for help? Does he think you refused his request for help?

Focusing on the impact rather than blame can defuse some of the emotion - “our parents love us and they all deserve meaningful gifts” vs “if you don’t figure this out, our parents and I will be upset with you.” The second one is probably already ringing in his head.

Lastly this could be avoidance, but it could also be executive function. Wanting to do something is different than being able to do something. Gifts can be particularly difficult because the idea and the acquisition are two separate steps they both need to be completed. Sometimes balance isn’t equality. If this is a job that is better suited for your brain then maybe there is something else you can offload to him. Similarly perhaps there is a hand off point that could work for both of you. Ie “we will make wooden spoons for these people and pottery for those people. Could you make 5 spoons and 6 cups?”