The other sources I read say it severed the subclavian artery and broke the clavicle, which is in the shoulder/neck area.
He had several other wounds, and blood from four other people on him. Blood from two are on his arrows, another on his dagger, another on his clothes. The speculation is he killed two-four people before he was killed.
The arrow shaft is missing. It may have been pulled out.
However, the copper axe he had was worth a kings ransom at the time. (Kingdoms were very small back then). The axe was left, the body does not appear to have been plundered. Perhaps Ötzi inflicted severe enough wounds on his attacker, the attacker retreated and was unable to return.
It may have been one of those, “you should see the other guys” kinds of things.
Where was the copper axe found? Hidden under the body or lying out where it was visible if someone ran up and pulled the arrow shaft out of the body? Are there customs about recovering the weapon that killed an enemy?