Answer

1. I indeed do not share the assumption that this involves a moral prohibition, though such an act may well be immoral. But the halakhic prohibition involved is not a moral prohibition. In my view, morality and Jewish law are two independent categories. So, for example, in my opinion the prohibition of “Do not murder” is not connected to morality. It is a halakhic prohibition, even though in parallel there is also a moral prohibition here (since murder is of course immoral).
2. This can also be examined on the halakhic plane. For example, if I caused someone to sin under coercion. Nothing happened to him, because he acted under duress. But I still violated “do not place a stumbling block before the blind.” Seemingly, this shows that “before the blind” is not a prohibition between one person and another person (since I did not cause him anything), and from that it is clear that this is not a moral prohibition. One can certainly analyze this further, but here I only want to illustrate a way of thinking.
3. The question whether this is a teleological or deontological prohibition can arise even if the prohibition is halakhic and not moral. You can still ask whether the prohibition is on the act of causing someone to stumble, or on causing a problematic result.
4. This question itself can also be asked on two different planes: (a) the purpose of the prohibition (is its goal to prevent the result, or the act of causing it itself); (b) the halakhic definition of the prohibition (is it defined as a prohibition of causing someone to stumble, or as a prohibition of causing a problematic result). The halakhic definition does not always correspond to the definition of the purpose (the reason for the verse) of the prohibition. For example, the commandment of procreation, of bringing children into the world, is ostensibly aimed at achieving a result. But its halakhic definition (what is incumbent upon me) is the action itself—marital relations—because only that is in my hands. The result is not in my hands.
5. Even regarding morality, the question of deontology can be formulated in two completely different ways: (a) what defines an act as moral (its consequences or the type of action); (b) why do this act (because it brings about the desired results, or because the act is intrinsically positive).
6. As for your question, I do not know where in the passage you see a discussion of the deontological versus utilitarian/consequentialist question.
7. You will not find direct halakhic discussions of this question and similar ones, because Jewish law speaks in the language of actions and prohibitions, not on the level of reasons. One can try to infer from the laws regarding the nature of this law (whether it is deontological or not). The literature of Jewish thought is not familiar to me. I do not engage in it because I do not think very highly of it. So unfortunately I do not know how to direct you to the relevant literature, if such exists.
8. If you have a concrete question, I suggest you formulate it precisely and clarify what exactly you mean (according to the different planes I described). Once you have such a formulation, it will be possible to think of a case where the halakhic ruling would reflect a deontological or teleological stance, and based on that to look for a source that gives a ruling one way or the other. (That is basically to put the theory to an empirical falsification test, instead of looking for it in an a priori philosophical explanation.)
For example, one could ask whether there is a prohibition of causing someone to stumble when I try to cause someone to sin, but in the end, for some reason, he does not actually violate the prohibition. For example, I handed the cup of wine to a Nazirite, and he decided to pour it out. Or he drinks it under coercion (so that for him there is no transgression). And so on. What about causing Reuven to do an act that in my view is a transgression but in his view is not, or the reverse? (This is a test case for the question of pluralism in Jewish law.) Once we have a test case, we can look for sources that issue a halakhic ruling about it, and from them infer meta-halakhic conclusions regarding the question from which you started.
All the best,