many have written about a dedicated mic/handset for PA announcements and YES this device would have prevented the OOPS if properly used.
Someone mentioned that this would be difficult to use if on oxygen/masks.
We had an FAA approved technique for using the PA handset while on Oxygen Masks.
Simply USE the mask interphone/com which goes through the overhead speakers, make the announcement by holding the PA handset next to the overhead speaker and press the button(s) and talk.
Worked fine.
IF IT CAN HAPPEN, IT WILL HAPPEN...murphy's first law