Liar Liar, Pants on Fire!

This past week the investigator from the department that I reported Rob's family to called to update me on her findings. She told me that when she went to the house, she asked Rob to show her the knife that his brother cut him with. He went and got his mother's shaving razor and showed it to her. When he showed it to her, he ended up cutting the top of his finger. She asked him if that's how he cut his finger, and he said, "yes". Then when his brother came home, Rob started apologizing to his brother for making up the story. She also said the mother was very upset and showed the investigator how they hide all the sharp objects in the house and put them out of Rob's reach because he is "obsessed" with sharp objects.

OK. So last year I had a meeting with his mom and told her about how he cut his own hair with scissors, cut holes in his clothes, and took a razor apart and put the blade in his mouth! She NEVER mentioned that she has to hide the sharp objects at home. She just said, "OK, I'll talk to him." Like it doesn't even faze her. I'm sorry, but what the hell, lady? You would think she would tell me about this - so I could be reassured that she is also concerned about this situation and handling it. You would think.
So I end up feeling kind of duped for calling and reporting this incident. Yes, it's better that I call just in case; however, this situation reminds me of the fable, "The Boy Who Cried Wolf." Rob has been know in the past to make up stories. For example:

1. Last year he said his brother took a cell phone from Best Buy. When I asked his mom about it, he said, "Ha ha - I tricked you! The lady gave it to us." Turns out it was a display phone that a Best Buy employee was throwing away, so she just gave it to him.
2. A few weeks ago he moved Lacy's clip down one spot on the behavior chart. I asked the class if anyone moved the clip (If they touch a clip it's automatic blue, which means phone call home). He said, "no" when I directly asked him. Then I said to the whole class, "If I find out someone moved the clip and lied about it, he or she will get a detention. So if you moved the clip, you should tell me now." Sure enough Rob said, "OK, I did it."
3. Last year he came to school and showed me his new watch. I asked him where he got it, and he said, "I got it at Wal-Mart. I stole it." "You stole it? Why did you steal it?" I asked. He said, "My mom told me to. She said we didn't have enough money. I got one for my brother too." Now I don't know if this story is true.

Like I said, "The Boy Who Cried Wolf."