It's possible that the "minimum success criteria" or "primary objective" of the mission was to touch down intact within a radius. If that was achieved, then I think even in English it is reasonable to call the landing "perfect" in that it achieved all of the mission goals.

But that all depends on whether, "land upright and measure things with the expensive instruments we sent it with" was originally included as a primary objective and whether they've just moved the goal posts to minimize the appearance of the failure.