How, as an audio person, would you prefer to be made aware that the foley/perspective was off-target?
It might sound strange from your perspective but I've never really thought about what I prefer, I just accept the way it's always done, which is one of two ways: Either there is a final mix phase, at which the director is present (usually along with the producer and sometimes the pic editor too). During this final mix the director or producer will ask for the playback to be stopped at any time and simply say; they don't like something or something is not working how they expected/envisioned, that they want to try switching a particular sound effect, that a particular element is too loud or too quiet, that the pace is too slow or the "feel" not quite right, that a sfx is missing or that something not previously mentioned needs to be added to draw the audience's eye to a particular visual event/element, etc. I make the changes there and then or if it's a more major/time consuming change, I do it once they have left for the day and then we review it first thing the next day. The other way is when I'm working remotely; I send the director an "approval mix" and a day or so later I get a list of comments/revisions.
I don't expect (or get) insults/abuse and likewise, I don't expect the director/producer to "pussy foot" around, trying to avoid the possibility of hurting my feelings. I just expect a brief, direct instruction of what change to make. Of course, this process isn't always entirely as efficient as it sounds, occasionally the director or producer may disagree with each other, be indecisive or not be able to express themselves clearly, in which case we can end up going round in circles a bit but generally this is rare, especially with the better/most experienced directors.
In my situation I'm a paid professional, working with professional directors and producers and my job is to; meet technical requirements/specs, get the aesthetics ("feel"/emotional response/shape) the director and producer want and to achieve this efficiently, effectively and within the timescale agreed. I'm not sure how applicable any of this is to your situation though. Your sound guy is not a paid professional, appears to be more of a music production guy than an audio post guy and technically/legally you have already approved the mix anyway. On the other hand, if he's eager to learn/improve the audio post side of things, he might be grateful of the additional constructive criticism. You're going to have to judge for yourself whether you should just let sleeping dogs lie with this short and be more observant/assertive on your next project or whether it's worth re-hashing this one.
Just to be clear, I'm not saying the sound currently is bad, it not, I've certainly heard far worse! I'm just saying that the sound could have more effectively dragged the audience even deeper into the realism, drama, tension, pace, aggression, etc., of the main part of your short, created an even more dramatic contrast with the ending scene/sequence, making it even more surprising/amusing and thereby significantly enhancing the telling of your story.
G