I was impressed by the fireball at ignition. Seems like a lot of transient hydrogen around the base. Also, it appeared there was some flame around the edges of the base as it initially climbed out. Seemed strange.
http://www.spaceflight101.com/delta-iv-heavy-nrol-65-launch-updates.html14 seconds before T-0, the Radially Outward Firing Initiators (ROFIs) ignited beneath the three Main Engines to burn residual Hydrogen that was released during the fuel-rich start-up of the RS-68.
Employing a slightly modified ignition sequence, the Terminal Countdown Sequencer of the Delta IV assumed control of the countdown at T-10 seconds. At T-7 seconds, the Main Fuel Valve of the starboard RS-68 Engine was opened as the engine started its ignition sequence. This single engine was started earlier in order to reduce of the Hydrogen flame that is known to erupt from the launch table during engine start. At T-5 seconds, the Main Oxidizer Valve on the starboard engine opened and the RS-68 soared to life. At the same time, the remaining two engines started their ignition sequence by opening their Main Fuel Valves. Visually, the hydrogen flame engulfing the Delta IV appeared smaller than during previous launches, indicating that the staggered ignition sequence achieved its goal.