Saying “Given that he would be dead otherwise” carries the implication “if doing X leaves you dead, and you value your own existence, you should not do X”, which is false in the case of precommitment. Being the type of person who is willing to kill yourself may increase your chance of staying alive, even though you are worse off when looking only at the branch where you got unlucky and the precommitment forced you to follow through.
Saying “Given that he would be dead otherwise” carries the implication “if doing X leaves you dead, and you value your own existence, you should not do X”, which is false in the case of precommitment. Being the type of person who is willing to kill yourself may increase your chance of staying alive, even though you are worse off when looking only at the branch where you got unlucky and the precommitment forced you to follow through.