From what I can gather these reports, it seems to find the Abudullahi Nadir guy - who was reported to be married to the sister of Sheekh Hassan Dahir Aweys - the son of Hassan Dahir Aweys was under surveillance for both American and Somali intelligence services.
They also avoid contacts and only have a few body guards they trust. They tend to stay in the bush or in safe houses in villages in deep Lower Shabeele and Middle Jubba regions.
However, it doesn't look like the son of Hassan Dahir Aweys was the target himself. And when intelligence services want to find a fugitive, every family member and friend of that fugitive is under surveillance. It is most likely that the son of Hassan Dahir Aweys wasn't aware that he was tracked and seemed was using his phones to communicate. However, most likely every bit of his communication was getting intercepted. And it is most likely his confidence that he was not tracked that eventually got him and his uncle (Abdullahi Nadir) taken out.
Law enforcement and secret services allow people who are tracked to develop the confidence that it is business as usual and nobody is following them. So it is this patience that eventually bears dividend.
This is how Saddam Hussein (AHUN) was caught. His younger wife fled to Lebanon after his government was overthrown. American and Jordanian intelligence tracked her to a small apartment in Beirut, Lebanon. They watched her for awhile. She traveled back to Iraq in order to get financial help from her husband. Saddam (AHUN) at the time only had a one guy who was communicating with him. She found out the guy and contacted him. Saddam didn't meet his wife but instructed the guy to give her money from an undisclosed location in Tikrit, Iraq.
The American intelligence through their Kurdish spies watched the guy and eventually captured him. He was tortured that he eventually gave up the location where the former president was hiding.
So in the case of Sheikh Hassan Dahir Awey's son, it seems he was tracked and his movement was watched, especially when he traveled to Middle Jubba region.