I found further information on the medical evacuation which occurred on the last day of the cruise. The aircraft were in fact US Military aircraft and the hand painted number was just a temporary number. The following is from the Huffington Post:
SAN DIEGO (AP) — The California Air National Guard has rescued a man who
fell seriously ill on a cruise ship hundreds of miles off the coast. The agency says crew of the Holland America line's Westerdam contacted
authorities for help late Saturday and changed course to reduce the
distance to shore.
National Guard aircraft reached the ship Sunday about 300 miles from Southern California.
The 73-year-old passenger, who suffered kidney failure, was flown to a hospital in San Diego for further treatment.
The National Guard crew was deployed from North Island Naval Air Station, Coronado.
Video of Rescue
Some pictures I got from a cruise critic discussion.
For more information and discussion clink on this link to the Cruise Critic Discussion
It's amazing what can be done in that type of situation and we can only hope the person involved made it to a hospital in time, a truly frightening experience.