Dear Stephen,

Thanks for the question.  

It sounds like your priest did something like a "general absolution," which is a bit of a controversy, inasmuch as the legitimate use of that is often abused and not done in the proper circumstances or manner. It is not a substitute for a proper Confession, particularly with respect to mortal sins.

That being said, sins are forgiven in the Sacrament of Extreme Unction or Anointing of the Sick, provided the proper form and matter are valid.  If every person there received the Sacrament legitimately, then what the priest said may be true.  The Sacrament itself is done on an individual basis, so I can't speak to the manner in which things were conducted.  

Historically, it was given to people with grave illnesses (at death's door). Still, since Vatican II, it is given a broader application, and virtually anyone who is ailing may receive it.

If you know in your conscience that you have unconfessed mortal sin, then you should go to Confession anyway, just in case the former scenario is accurate.

Peace,

Bob Kirby