On further reflection, what all these examples show is that Maranget's algorithm is only correct for literals whose equality you can test at compile time. Thus, not even locals will work using his algorithm. Regexes and functions will certainly not work correctly 100% of the time.
What happens is that when multiple unequal tests in the same column can return a truthy value, you end up with a decision forest rather than a decision tree. If the first decision tree in the forest has the first and third end-states, while the second tree has the second end-state, if you end up in the third end-state, you must still check the second decision tree before you decide which end-state is actually correct.
This is a shame, since it means that compiling the matches becomes more complex. On the other hand, it seems like a great subject for a paper at programming-language conference, so there's always that.
On a serious note, though, this bug is major, and you should consider removing support for at least guards, locals, and regexes until it is fixed. The bugs that arise from it in the end-user's code are really hard to track down – it's as if `or` or `and` were broken 10% of the time.