No, we can't know for sure, since both words can be used in both ways, but strangle is more often used if we mean that the person was killed.
The most potentially confusing thing in the definition that you found is that strangle is given as a synonym for choke. As is often the case with synonyms, it isn't an exact match, and has connotations that the other one lacks.
You're pointing to the fact that you could perhaps use both words to talk about squeezing someone's neck for a period of time, and about completely killing someone that way.
"Stop it! You're choking me!"
... said no corpse ever.
But there's a difference between the two words. When I look up strangle, many of the definitions I find assume that it means strangle to death:
- Merriam-Webster says "to choke to death..." and "to obstruct seriously or fatally the normal breathing of." The second definition says "or fatally," allowing a non-fatal use.
- Cambridge simply says "to kill someone by pressing their throat so that they cannot breathe."
- Lexico (Oxford) says "Squeeze or constrict the neck of (a person or animal), especially so as to cause death," again specially mentioning but not requiring a fatal definition.
In comparison, when I look up choke...
- Merriam-Webster leads with "to check or block normal breathing of by compressing or obstructing the trachea or by poisoning or adulterating available air," and never mentions death.
- Cambridge says "If you choke, or if something chokes you, you stop breathing because something is blocking your throat," again not mentioning death.
- Lexico says "(of a person or animal) have severe difficulty in breathing because of a constricted or obstructed throat or a lack of air," again not mentioning death.
So I would take all this to mean:
- Strangle can mean either choking someone for a period of time, or killing them by doing so, but much more strongly implies killing (one of the entries uses "tried to strangle" in an example)
- Choke is more often used for the activity alone
- Since both words can be used both ways, there is no way to be absolutely sure what is meant without context.
- "Tom [choked/strangled] Mary" —This may or may not mean that Tom killed Mary, though if you choose strangled, it will be more strongly implied.
- "Tom [strangled/choked] Mary but she is still alive now" —Yes, this is not nonsensical. Choked would be a better choice in this instance (and you could reword the whole thing to be even clearer, like "but she survived" to avoid suggesting a zombie scenario).