Hace unos días actualicé una pokeparada en mi población, colocando una foto más actualizada y la han cambiado a la foto antigua, lamentablemente en mi población ahí un tipo que se cree dueño del juego 
There is nothing wrong with it. Photo are chosen by voting. Just like you have right to pick photo, so do he. Noone own pokestop, just because you put in the most updated photo doesnt means your photo will be chosen. You can however spread gift and ask people to vote for it. When your photo have more vote (including old hidden vote counter from ingress) , your photo will be chosen.
But for the record, he also have right to ask his friend to get more vote as well.
So my advice is just dont get fixated on this issue.