People are confused about that whole segment, which is why they're finding that last scene awkward or this whole chapter being weirdly favorable for Al.
Both Laine and Euphie were generic damsels and puppets when they were Al's partner. The whole final scene, including what the TL page said was "awkward resentment", is meant for the two of them to show Al (and us) that they've become better and more independent people. And that if they ever have to deal with someone like Al again, they're not going to roll over and take it. No, Laine probably doesn't actually resent Al now, though she might still not forgive him to some extent. Does it need to be spelled out and spoonfed for people who can't read between the lines of something so simple?
As for Al's punishment being "lenient", this is actually pretty standard in medieval European monarchies. Try looking up various lists of executed royals. You will find very, very few, compared to how many monarchies that have existed in recorded history, with the majority of them being of non-european monarchies or the result of usurpation or overthrow of the reigning dynasty, which invalidates the royal status of the executed. With most European monarchies being heavily entwined at least in name with religion, and the often complex family connections with the greater nobility, it was very unseemly and politically fraught to actually execute members of royal families. There are even royals who have instigated wars AND directly tried to kill their siblings/parents/children/etc....and they've simply been exiled after the fact. Sometimes multiple times.
It's a different matter for assassinations, which was far more common and avoided all of the above problems. So if they really want AL to pay with his life, he'll meet an "accident" during one of the experiments or something. Obviously, everyone's said their piece in his favor so that's not going to happen. And if one wishes to be totally cold and logical about it, they can always quietly kill him later if he continues to be a problem.
I can't help but feel this crowd has read far too many manga in this genre which tends to be even more simplistic in character portrayal or pushes many fictional tropes about medieval Europe.
