The whole principle of double effect rests on the notion of a “foreseen, but unintended” result of an action. I submit that this is just another cop-out. If you can foresee the result of an act, and perform the act, then you cannot defend it by saying that it was “unintended”. You did it and that is all. The rational approach is to examine if the act was “justifiable” or not. If the act and the outcome can be justified, then all is well. If not, then we condemn the action.
But, of course that would bring in the dreaded proportionalism, and that is unacceptable. The whole thread dealing with the runaway trolley revolves around this question. Both the inaction and the action will result in some deaths. It is obvious that one chooses the option which results in fewer deaths - all else being equal. By the way, there is no need to have those people be tied to the rails - that only would allow to “derail” the thread… (yes, the pun was intended). Those people are simply there, and either one or four will die due the action (or lack of).
Another similar problem is the definition of “theft” - which is considered to be intrinsically evil. Now, not even Catholics would consider it evil to steal a piece of bread to help out someone who is about to starve. So, what do they do? Redefine theft.
Same applies “to lying” - which is also considered to be intrinsically evil. So what to do when a death squad is looking for some refugees? Redefine lying, too.
All those mental gymnastics, when the solution is so simple and obvious. Stealing and lying is perfectly acceptable in some cases, and unacceptable in others.