Question about warranty

[thefinestimage]

Quick question. I have an 07 H2, bought new back in 07' and it now has 32,000 miles on it. I brought it in this morning for an oil change, and tire rotation. I brought it into the local Hummer dealer, who have always been great to me. Anyway, the team leader calls me in to take a look at something, and he shows me a crack in the transfer case. He tells me I must have smashed it on a rock and now it has a crack in it and it is leaking pretty bad. I look at it and it looks like something is trying to force its way out from the inside, as the metal is pushing out, not in. He tells me it will only cost me a few thousand, and here I thought that it is under warranty. Is it? After I explain to him that something is coming out, not pushing in, he said I may have spun a bearing because I was stuck in mud and had to rev it too much to get it unstuck. He says all of this because he saw too much mud under the truck? I had to wait a few hours for the service rep to come in to let me know if it is covered, and he tells me he doesn't know until they take it apart? Why? INternal damage may not be? any one here have these issues? Anything I can do? They had it all day today, and not a call. Just wondering what I should or could do. I don't think I should have to pay a few thousand. Anyway, thanks for any and all help. Joe.