You can bet there would have been equipment in the area for ABC to get this tape immediately transmitted. If they received the tape on the weekend, it should have immediately been turned over to the Feds. Any tape purporting to be from a terrorists needed turning over ASAP. Saying they had to listen to it first -- why? Do they have anyone at their HQ that had the expertise to review the tape for content? No way!
IMO, this was all done by ABC to keep the attention on the weapons dump story to hurt Pres Bush and when that blew up in smoke they figured they had better turn this tape over to the Feds. No news organization with any integrity would have held this tape even overnight without contacting someone in the Federal Government.
MSNBC is reporting the CIA got the tape Monday:
http://www.freerepublic.com/focus/f-news/1258973/posts