This is not a medical forum, and I am talking neither cynically nor as a pathologist hereIf someone dies minutes after being pushed over, common sense links the death with that assault !
( Even if there was found to be a heart attack, the event triggering that event (death of an area of heart muscle by a thrombus / "clot" in a coronary artery, with a fatal abnormal heart rhythm) was the assault. Other events may also contribute to a heart attack). The condition may be natural but the underlying cause is not !
The second forensic pathologist, who is well respected, described injuries sufficient to support a charge of ABH (actual bodily harm), consistent with a baton strike (whether or not there was also a heart attack). I rest my case.