No offense but there's too much misinformation in this thread.
Mind and body are different but they are connected.
If something stabs your toe like a thorn, you react (it's not insentient body that reacts). Or you may feel pain but not react and just know it's there.
Why do I say this? Look at the case of Thich Quang Duc, the monk who immolated himself and died. His whole body was on fire and yet, he was completely still. He didn't move at all. His whole mind was completely accepting of his condition.
But in his case it was a suicide out of compassion.
I suppose what happens for most of us is... we don't really want to die, we want the suffering to stop. This is different.
I think if we still force a suicide and our mind isn't completely ready/in sync with the action, then there will be SI.