I would argue though that no, being able to talk to the owlbear adds NOTHING to the encounter. You can't talk your way into being able to assist it and retrieve the spear point peacefully. Nothing changes other than getting a couple lines of dialog from a monster.
If you look only at the possible outcomes, you are right, nothing changes. However, this is a roleplaying game that heavily focuses on player choices, and making you feel like your choices matter. Some such choices are simply creative ones, or even funny ones, but they add to the replay value (if only minorly) as well as help you roleplay your character.
I can certainly envison a D&D session in which my party meets an owlbear, and the ranger of my group going: 'can I try to befriend the owlbear?' And my DM would probably go: 'yeah sure, go for it!'
instead of insisting that it isn't possible because of wrong creature types. That's what makes D&D so great, to me.
