Ha! Grand theft ram! I love it. But I do not agree that Poseidon really has any cause to take Odysseus to court. I agree with the first answer that this stuff is what Poseidon should say, but Odysseus will win unless his lawyer is an idiot.
Odysseus didn't just go and do that stuff to Polyphemus for no reason. Everything he did was done in self defense. After all, Polyphemus did eat a whole bunch of Odysseus's pals. Courts tend to take that sort of thing into account.
Now I would say that you might also want to bring the whole deal with Palamedes in if you were Poseidon. I think that is a pretty strong reason to hate Odysseus.
Have you ever heard or noticed someone getting upset about another person picking on their family, but then turn around and pick on their family themselves? That is what's at work here.
Posideon has grounds for taking Odysseus to court in that:
1. Odysseus committed assault on his son. Polyphemus had his eye burned and singed. There were eye witnesses and accomplices. A plan was thoroughly discussed and enacted.
2. Odysseus committed fraud on his son. Odysseus claimed that his name was Nobhdy. Only on a binding document would this ever matter, so this one is shaky, but worth a try.
3. Odysseus harassed his son. The name Odysseus declared prevented Polyphemus from receiving any help from neighboring Cyclopes.
4. Odysseus committed grand theft ram. Odysseus loaded several sheep, goats, ewes and rams onto his boat upon departure.