What the daycare director has to say about Vinny.

So, this morning when I dropped Vinny off, I started to talk with the daycare director. I was telling her how he has become such a tattle tale. He is always worried about what someone else is doing naughty and drags whatever adult is there over to show them. I think it's funny. She says that it isn't very normal for a child that age.
She told me first thing, that she isn't a Dr, she is only speaking from experience, but...
She told me that she honestly feels that Vinny is intellectually about a 3 year old. He thinks like a 3 year old, and processes and concentrates and just "gets things" like a 3 year old. He notices, and connects things together, and when he processes information, he does it in a way advanced way. Yet, he talks like an 18 month old. He still isn't talking much. He says like 10 words and signs like 8, but does almost any animal sound that you ask him to.
She thinks that is why he yells, and hits, and bites so much (although he isn't biting anymore.) She said that she thinks that he thinks in sentences and paragraphs, but only can say one word at a time. She said that sometimes it takes longer for the muscles and vocal cords to develop, that allows the children to be able to talk, and she thinks that that is the case with Vinny.
I know she isn't a doctor or an expert, but she has been in childcare centers for over 25 years, so I know that she has been around children a lot!
He has been doing great since they moved him up into the toddler room. He has a hard time when I drop him off, but when I go to pick him up he doesn't want to leave.
Any thoughts? I don't know what to think about the whole thing...