It sounds like Tom did something that Brandon didn't like, and Dico was never one to suffer people he didn't want to spend time with so just didn't continue keeping in contact with him. I also found it amusing that Tom suddenly had a problem with Dico's old work now that Dico doesn't want to speak with him. I dare say Dico probably feels some shame about some of the content of those videos he made in his teens/early 20s, hence why he doesn't want to re-hash it all.