A couple of things:
- "Top talent" is an awful term. You only hear that from viewers externally. Well, maybe from a couple of on air talents when referring to themselves, but they'd be the exception.

CNNI is a different game to the domestic network in that respect.
- Isha is normally still in the newsroom on a Friday for a few hours. There would be no need to call Isha in specially for on air as Jim would probably have gone upstairs with Randi if Isha had not been in.
- Atlanta will always handle breaking news unless the studio is tied up with CNN en Espanol recording for their air or International using it for a pre-record. London will break in on those occassions and has in the past. They can't do it all the time as the London studio is often in use during Piers Morgan, normally a pre-record for CTW. Breaking news is usually always produced from Atlanta during our dayside hours as well, so it's a lot easier for us to break in. Atlanta is never more than a few minutes (at most) from being ready to go live no matter what time of the day. As noted, logistics, logistics, logistics.
- Jim starts at work really early. He wasn't scheduled to anchor more than 90 minutes with Suzanne before Hala was to relieve him. I don't know when the decision to simulcast with domestic was made, but The Brief was going to run as scheduled on international until around 9:30 eastern, but I digress. Once Wolf picked up coverage it would have been awkward for Jim to handoff to Hala during this rolling period. Please note that there is a significant difference to rolling coverage of protests and the president stepping down. The latter situation is a lot more critical in terms of coverage and the network wants to have a team that can go for hours if need be. It would have been ideal for Wolf and Hala to kick off coverage at the top of the hour, but these decisions are made on the fly and will always be subject to differing opinions in hindsight.
- As also noted, Anderson and Hala were in Egypt covering the story on the ground. Anderson and Wolf were always pinned to anchor coverage should the president step down. Those plans were made a few days ago. Hala probably was tapped to help out too, but I'm only taking a guess with that. At the end of the day, it's all about stable team fronting the coverage. Events move so fast that it can be confusing for viewers to keep up with, so there's no need to add more confusion by swapping and changing anchors.
- I don't know if it's been announced yet (I've finished for the day and out) but Fionnuala Sweeney will be on the ground in Egypt.