I don't think journalist really have an important information that make them able to predict which team will win.
Both coach and player will stay calm if they get interviewed whether it's official or just small chit-chat, there's no one know the reality except the one a part of management. People who work behind the team know much about the team.
The sports journalists are more informed than we because they go closer to these guys than we do so they could actually be at a better position to under their gameplay, read from their strategies and tactics and to be able to make their judgements from there. But in all of this, the sports journalists are not anywhere better than us because they are also going to just predict the outcome but are not sorcerers to magically predict sure wins. They don't have the spells yet.
The sport journalists can not tell what will happen inside the football pitch. They might have a better informations about the game but that will not still stop them from losing the bet if they gamble on it. I think the real deal is not by the information you have but by what actually happens on the soccer pitch. So long as the game will not be rigged then the soccer journalist will know what will happen.