How can someone file a lawsuit like this?

Tweet

About 9 years ago, my son moved out on his own and got an apartment with some friends. Halfway through the lease, one of his roommates was caught for breaking into cars in the parking lot so all 3 of them were evicted. My son had left his forwarding address, even though the other 2 did not. Shortly after that, he got a call saying he owed on the rest of the lease and some damages. Well, he did the responsible thing and paid his third. He never heard from them again, until late last year. He and the other 2 had been turned over to collections for the remaining balance. I work with some lawyers, so I called one up and just asked if there was anything we could do about it. I found out that the statute of limitations to collect on a lease is 3 years. He said to just ignore it since they couldn't do anything any more. Well, last week, my son was served papers to appear in court for a judgement. Part of the paperwork includes copies of the lease and damage report - all dated in 2003. So, my question is (and I've asked my lawyer friend, too) is doesn't anyone look at the documents being submitted with a lawsuit? I mean, you'd think they would check the dates to make sure it's legit. And this is being handled by a law firm, it's not like the landlord is just filing all this on his own. I can't wait to hear back from my lawyer friend, but tell me what you think.