Unexplained things from Jan 6

 There was that video showing people streaming into the capital building while a cop held the door open for them.  They showed that several times back just after Jan 6 but I have not seen it all lately.  I don’t understand that one at all. 

On the day after (7 Jan) both the Master of Arms and the Senate security chief resigned.  I have never seen or heard an explanation of that one.   Were these two men so ashamed of their performance that they wanted out, now?  Did someone in power like Nasty Pelosi or Chuckles the Schumer want them gone?  Something else?

The Democrats are planning hearings about Jam 6.  I wonder if either of those two questions will come up, and if they do (not very likely), what answers do we learn?