Um...in the end, the fact that he knew the truth at any point and withheld it is intentionally lying. It's pretty much a textbook definition of it. Doesn't matter the reason why, particularly since he was reaping seeming benefits from it. It's no different than Clemont trying to divert attention from Clembot taking over his gym, which was treated as a lie there, as well. Maybe not the same magnitude but still...a lie is a lie.
Having finally seen the episode, I can see that even with my no knowledge of the Japanese language (though some people have also clarified), none of the criticisms about Sophocles is really valid. If you don't like Sophocles fine, but don't put him under a category of scum a category doesn't belong.
Now if I understand correctly:
1. All Sophocles knew that he was moving it wasn't until near the middle of the episode he realized he wasn't moving all that much.
2. Kiawe's "gift" to Sophocles has to be ignored because if I understand the timeline, he STILL assumed he was moving away and only learned otherwise AFTER Kiawe taking him to a volcano.
3. After learning the truth, Sophocles was terrified of their potential reactions, and therefore was unwilling to reveal what was going on.
4. Lana then took it upon herself to take Sophocles to a sunset and Wailord watching (or something close to that)
5. On the supposed last day everyone parted ways while Sophocles DID try to tell everyone at that point, but everyone hurried up.
6. I assume he was at Mallow to try to tell the truth, I assume that because Mallow forced him into the restaurant, if he was the scum everyone is criticizing him for, apparently then he would've gladly walked in.
7. Meanwhile to the ignorance of everyone else, Ash was trying to give Sophocles a Pokemon gift.
8. While celebrating Sophocles's farewell, Sophocles while enjoying the food, was completely uneasy about the whole situation, with the added guilt of not being able to tell. Cue Lillie crying.
9. Ash returns, leading to Sophocles catching Charjabug.
10. Everyone is saying their final goodbyes, resulting in Sophocles crying because he couldn't handle the guilt of not being able to tell them sooner that he wasn't actually leaving, just moving a way, and he was sorry for everyone who was being nice to him because he left, but instead of them reacting the way he thought they were relieved and happy he wasn't leaving.
The only fair criticism that I can think of Sophocles, is that he must think of them lowly to assume that they would stop being his friend just because of a misunderstanding.
But everything else is not what I would consider valid criticism.
Sophocles did not LIE to benefit everyone treating him nice, if you think that, then I would question your logic here. If it takes Sophocles leaving for his friends to be THIS nice to him, then how is Sophocles in the wrong here? Sophocles barely benefited and didn't fully enjoy what he was getting. As I said Kiawe has to be excluded immediately because Sophocles only found out the truth afterwards. The most beneficial thing that Sophocles ever received in this episode was the food Mallow made for Sophocles. While Kiawe (to generally add him to this not that it counts) and Lana could easily had been more friendly to him and offered him the things they gave him before.
Now I suppose there is Charjabug and Ash, but I wouldn't consider that truly beneficial since even though Ash did put effort into bringing Charjabug to Sophocles, Sophocles did battle and catch it like a normal Pokemon, not entirely sure Sophocles "benefited from lying" as people claim. Especially since there was literally no way for Sophocles to admit the truth to Ash before that happened except for the Lana day, and even then there's a couple of problems: Sophocles was entirely caught up in his fear of what his friends would say, and more than likely was caught off guard with Lana.
By the next day they all left before Sophocles could admit what was going on, and unless he specifically went to Kukui's house to talk to Ash first, there's probably no way Sophocles could've stopped Ash from getting Charjabug.
Like I said the only fair criticism is Sophocles doubting his friends and what they think about him. Everything else, not so much. Especially with the consideration that they would only be THIS nice to him and do THESE kinds of things just because he's moving and this is THEIR farewell gifts? Kind of think Sophocles is okay enjoying these moments.
However if we go back to Mallow, I don't know if Mallow can be included here since she has done these things before, she does work at her family restaurant, and I feel like I said, this is probably the only one I would argue would be Sophocles's fault, at least to a point. I don't know if the restaurant was normally closed at that time, and Sophocles was just an exception, or that Mallow reserved that time for Sophocles, I don't know if Mallow used special ingredients that she can't use willy nilly but could because of what she thought was Sophocles's farewell, the only thing truly questionable but I expect Mallow would've done it for certain special occasions was the Sophocles and Togedemaru decorations on the food so even then I don't think that was truly out of the wall for Mallow.
But kind of shame on Kiawe and Lana if they were only doing those things because they thought Sophocles was leaving. It was nice gesture, but something you couldn't have done before? I mean sure, I do get the idea that you do normal things with friends on a normal day but for special days you especially go out, but hanging out with Sophocles didn't exactly strike me as going all out for your friend because of the occasion that it was. I'd say Kiawe might be more justified than Lana since Kiawe took Sophocles to Akala Island, but Ash has visited Akala island so unless Kiawe would normally only hang out with Sophocles on Melemele Island, I'm not seeing how much of a special occasion it was or how much effort it was for Kiawe to doing it. But it was more extreme than sunset and Wailord watching unless it was a seasonal thing and Lana was hoping to do it with someone else.
But yeah, I'm not seeing the hate being justified for Sophocles.