I don’t know that there’s a significant difference in that tack. You’re saying that the tram driver can force a change in tracks, but cannot stop the tram in time? This only affects the consequentialist’s analysis, no? After all, “greatest good, greatest number of people”, right?
But, for Catholic Moral Theology, it’s still a matter of “I’ve discovered a dilemma; I can act in a way that’s immoral, or I can choose not to act in a way that’s immoral.” (Of course, to your point about a “court of law” argument, the real-world response would be “I tried to do everything I could to stop the tram, but was unable.”)
(Side tangent: OK, @AlNg, what’s the funkyness with your user name? If I type “@AINg”, it doesn’t transform into a handle. But, if copy & paste from your username, it does. Then, if I retype the ‘A’, ‘N’, or ‘g’, it stays a handle. But, if I retype the ‘I’, the handle goes away and it’s just plain text. So… what character is this, that has the appearance of an “I” but is not an “I”? )