HBO released the episode three day earlier than its original air date through their online streaming services, because it was scheduled to air during Super Bowl Sunday.
Wayne states that the backpack must have been planted at Woodard's house and couldn't have been present when the "mortar" went off. The device triggered at the door is actually a claymore mine, an antipersonnel mine commonly used by U.S. forces in Vietnam and many subsequent conflicts.
When Wayne is at Elisa's place, the iMac she was working on is visible in the background as they speak. You can see she was editing video on Adobe Premiere Pro.