I was going to hide the outtakes as an easter egg somewhere in the campaign but eventually decided they fit best in the credits.
As for getting the Centauri official (you) on the Hadrius to make contact with the player:
1.) Scan any of the Centauri cargo pods.
2.) Get away before the patrols are asked to "escort" you away, or
3.) Without shooting at the Centauri fighters yourself, lure them over to the Narn (Ja'tan wing) on the other side of the station to get them off your back.
If shuttle Hadrius hasn't launched at that point, it will soon. Provided you haven't spilled any Centauri blood yourself and you aren't actively engaged in hostilities with one of the factions at the station (the Narn, security, somebody else...), the guy on the Hadrius will contact you.
I forgot Ker.Soth asked if Alpha is guardianed in the last mission. Alpha is actually protected or made invulnerable at some point in every mission except the third. Good catch!