Ah, i wasnt able to find the phone. I think i clicked through his dialogue too quickly (was the first NPC i talked to in the town) and i missed out on what to actually look for.
Viewing post in Nothing Strange In Mentira Town jam comments
He has random lines, some of which are pretty funny, specially after you give him the phone and he goes to the alley. I think I should have mentioned in all of them that he needs the phone hahhahha. Thanks to you I added a small guide in the game's page, since it can be a bit hard to follow the story if you don't read everything really carefully and check everything. I really recommend playing it until the end, it's really short!