Two points to consider Shadow:
1) If your friends were on one of our shiny new Airbusses then they don't have HF fitted.
2) If they weren't on an Airbus then the HF fitted may not actually have been serviceable.
Without HF comms none of our shorthaul fleet have a quick or easy way of contacting Medlink - VHF frequencies change every few minutes and the ACARS system is both very user unfriendly and totally dependent on info from the Assessor, who is course busy saving some ones life. To be quite honest if the situation is so serious that no time can be spared to speak to the flight crew then we need to be tolds. That means if people aren't breathing, or are bleeding uncontrollably, or are in agonising pain, or are turning blue in the face then we need to know. Over 90% of our short haul network we can get the aircraft on the ground within 15 minutes, faster than we can establish useful two-way comms with Medlink. If the situation is serious they're going to ask us to divert anyway and we'd rather get on with the work than mess about with ACARS. If the passenger looks like they're going to live then it's safer overall for us both to be flying the aircraft as fast as possible to destination than disregard all normal checks and procedures whilst one pilot is completely out of the loop.
In summary, for short haul Medlink is a useful tool, but only if you've got lots of time spare to wait for a response. If the situation is time critical then tell us and we'll land the thing without waiting for Medlink.
Of course, disregard the above if your friends were on a long haul flight over the middle of the ocean!