After recently installing GSX Pro onto a new system I'm finding strange system freezes which according to event viewer relate back to "couatl64_MSFS.exe".
Couatl64_MSFS.exe, being an external .EXE, by definition, cannot "freeze the sim", since normal .EXE applications don't have any access to the memory used by another .EXE, this is not under discussion.
However, if the SIM crashes for other reasons, Couatl .EXE CAN affected by it, because the crash in the sim would abruptly interrupt the normal communication through Simconnect, so Couatl will likely be unable to exit cleanly in this case.
So, what you are looking in the Event Viewer, is Couatl crashing because of the sim crashed for other reasons, but I'm sure you must ALSO have Events showing a crash in Flightsimulator.exe, which is likely having an earlier timestamp.