Ashe died of a heart attack. The medical examiner clarified Ashe died from traumatic asphyxia laryngeal fractures (while lifting).
The completed autopsy report will be available in 16 weeks....
R.
http://www.cnn.com/2016/06/22/us/united-nations-john-ashe-dies-while-awaiting-bribery-trial/
Dropped a barbell on his neck?
Not impossible.
Though it seems suspicious, I suppose, from what you write, he could have had barbell over his head, had heart attack and it just so happened that as he collapsed the barbell came down on neck?/back of neck as some say, causing the asphyxia/neck fracture.