The services of a soothsayer would not be needed to find out that the dude didn't even get to enter the apartment.
How was Gregory Ronnins even able to find out the whereabouts of Adriana Hastings? What was the relationship between them? The Hastings and the Ronnins were not known to be allies, not as much as Aiden is informed. What did they go out of town to do anyway?
The relationship between Aiden and Adriana happens to be a delicate one, and he wouldn't want to stress it further by having his men tail Adriana. She would obviously kill them all and take it all out on him.
Aiden literally had his hands in Adriana's mouth, and violence is not even an option he could adopt. As a result, he decided not to go looking into anything that had to do with Adriana. Once he got his drive, every other thing between them ended there. They all go their separate ways.
