Alex contacted Saahira, knowing there was a very good chance that she had stayed behind and saw what happened. His thinking was correct, and the details he received were not much different than Andrei shared, but it still gave him significant insight into the whole incident.
Evangeline initially sought Alex's location through a request tinged with an implied threat, and when Andrei questioned the consequences of non-compliance, she escalated to outright threatening them with torture.
Evangeline made it clear her goal was to meet Ruler, and she didn't mind going a bit overboard to acquire what she wanted.
But Saahira believed that while she was threatening to torture them, Evangeline was making sure not to go overboard because she not only kept her focus on Andrei but didn't even make an effort to stop her from making her escape.
