Yes it has been discussed before,
"How did Delta take his helmet off if he is grafted in to the suit?"

We know that he should have been grafted into the suit based on Suchong's diaries and the fact that Suchong died before other protector models were made.

But now I have proof that this whole helmet business is a narratological goof.

If Delta took his helmet off then, technically, all of the special ADAM that works as mind control should have come spilling out! The suit is filled with this ADAM to keep the Big Daddies somewhat drone like, and it probably also keeps them alive, gives them extra human strength, etc. Forget "How did Delta have his helmet on when he woke up" and start asking "Who refilled him with ADAM?"

The suits are filled with ADAM, that is what the yellow glow is. The Art Book confirms this.

So, off with the helmet=no ADAM = either
a)dead, and dead for good
b) alive and mind-control free but in a freaky suit

So any thoughts? I am open to being dis-proven.