No, despite your illogical attempts to make it so, it isn't.
A body is just a body. A collapse is just a collapse. Unless there is some EVIDENCE of FOUL PLAY. In this case, there is NONE. The fact that she collapsed, in and of itself, is evidence of nothing other than that she suffered cardiac arrest.
And in an attempted murder -- some evidence of a person coming close to death. Here, Terri's collapse is that evidence.
You really don't get it, do you? You are ASSUMING that it was an attempted murder, and then using the fact of her collapse as 'evidence'. This is an example of the logical fallacy known as the circular argument.
She collapsed under suspicious circumstances since no cause has been found. That leaves the door wide open.
The fact that she collapsed, in and of itself, is evidence of nothing other than that she suffered cardiac arrest.
Spontaneous cardiac arrest? I think not.