The pilot refused to let President Obama board until he honoured the Marine.
Hoax or Fact:
A story along with a video shared heavily on social media sites purports to show that a Pilot of a Marine helicopter refused to let the US President Obama board until he honoured the Marine Corp standing at the bottom of the helicopter. At first glance of the video, it does appear like what is said is true, but no, the claim as such is not a fact.
As you can see in the video, President Obama salutes the pilot as he enters the helicopter, gives hand shake, and exchanges some words before walking down to meet the Marine Corp standing at the bottom of the helicopter. Note that Obama then shook his hand with the Marine, exchanged few words with him, but did not render any 'salute' as such. It was as if he has just forgotten to address the salute offered by the Marine.
The incident in question happened on 24 May 2013 while Obama was boarding Marine One to go to Annapolis, Maryland, for speaking at the U.S. Naval Academy graduation. While some media outlets reported that President Barack Obama forgot the protocol to salute the Marine Corp before boarding Marine One, there is no such regulation that stipulates Presidents must salute the troops. Marines themselves are taught not to salute out of uniform, so the Presidents, in suits and ties, who are not wearing uniforms, are not obliged to salute the troops. However, since the President of the United States is the commander in chief of the United States Armed Forces, he can supersede the protocol and address the salute out of respect. Obama usually does salute the Marines out of respect (see last picture in Image Gallery), but it is not as if he's required to. As a matter of fact, Ronald Reagan is thought to be the first US President to have started saluting the troops in 1981; it was something he made up one day. There was no such practice before.
Considering the aforementioned facts, the story saying the pilot of Marine One refused to let President Obama board the helicopter until he honoured the Marine Corp is certainly a hoax.