[duskwuff]

Yes. And it only became relevant if you exploited a race condition by ordering the building to land, then ordering a siege tank to move under that landing point while the landing animation was in progress. You couldn't order a building to land on top of a unit, and a queued order to land would fail if any units were in the way, but once the building started to land, it wouldn't stop, and any units under it would be trapped. The bug fix added a second check which would kill any units under the building when it finished landing.

In principle, you could do this with any unit, but it was mostly useful for siege tanks, since those were the only Terran ground unit which really benefited from sitting in place.