“can catch” and “will take action” are totally separate things. I’ve not actually seen or heard a story where incompatible, overlapping bookings (we aren’t taking about actual duplicates, I.e. 2 of the same person on the same flight) caused someone to have a unilateral cancellation by DL.

And there are multiple legitimate reasons to have overlapping, incompatible bookings. It would seem extremely business traveler unfriendly (and not business smart, given DLs overbooking and load prediction ability) to unilaterally cancel incompatible, overlapping bookings.