First: I think Sabeel's mother received a call from UK enquiring whereabouts of the SIM card owner (i.e. Haneef).
Second: I think she in turn called Haneef's brother and informed him about it. And also she might have told him that Haneef's SIM card put her two children in trouble.
Fourth: Haneef's family feared and told him to leave for India from Australia
Fourth: I think Haneef's father-in-law bought him a ticket because he was not having money to go to India.
Fifth: Haneef chatted with his brother.
Sixth: AFP arrested him in the Airport.
My Conclusion: Haneef came to know about the attacks only through Sabeel's mother. He was not having any knowledge about the blasts in UK, prior to the attacks. He tried to call UK police to let them know that he is nothing to do with the attacks. So he is not at all a suspect. He merely feared because he is living abroad in a foreign country that too alone. That's all.... Is this a crime???????