When Echo is hiding behind a wall as Clark is calling for her, she puts her palms lightly to her face to apply war paint. When she removes her palms, the paint covers areas of her face which her palms did not touch and shows horizontal finger marks which could clearly not have been made by her palms.
When they were so short of time, they shouldn't have waited to reach the island in person to stage an entrance and tell Raven about their plan to go up. As the radio was still working then, they could have talked to Raven and told about this plan to go up so that Raven could have whatever she could have in the time they took to drive to reach Raven.