Can you owe 30 thousand dollars in taxes because of overstaying in US?

I'm a little skeptical about what my brother is saying and I want to ask if anyone has heard of this before I start asking him a bunch of questions...which always tends to tick him off. He is a US citizen, but 7 years ago, he began working overseas for the government in Kuwait, Egypt, and now Afghanistan. He is asking to borrow money because he says he owes takes. When asked how much, he said he owes $30k in taxes to the IRS because when he came to visit, he stayed more than 30 days in the states and because of that, he owes $30k because the tax exemption ran out. Is any of this possible? Can this type of scenario of some sort of exemption exist? When he first started working overseas, he was making $89k tax free supposedly (I'm just repeating what he said to me). His wife has came here in 2009 to have their baby and she stayed about 6 or 7 weeks, but he was here only about 4 weeks. Then she came again in October of 2010 to have a baby in December and is still here. He left after 2 weeks of getting her re-settled back in and hasn't been back since then...he didn't even see his son being born. Anywho...just trying to see if this could be true or have any validity before I disect the whole situation. Thanks