I thought that all almonds contained cyanide when green but were OK to eat when ripe.

You're quite right, Almonds as well as peach and Apricot kernels do contain cyanide (prussic acid), and the raw (unripe) almonds contain more. Everything is a poison it just depends how much you ingest. Drinking many gallons of water a day will eventually kill you.

Some countries, especially Eastern European, use green almonds and pickle them. But I do believe that all almonds need to be heat treated in some way to neutralize the cyanide. This is confusing because someone recently told me that the reason they heat treat almonds is to kill any salmonella that might be present. Does anybody know about this?

In Iran, we use the raw fruit in early spring (Mar-Apr)
and they are not bitter at all.

In every tree there are some almonds which are bitter.
And eating a few of those bitter almonds will not hurt you.

They also contain chemical benzaldehyde which has a strong odor.

eklogite

I've eaten almonds straight off the tree and am still here.

I think apple pips contain cyanide as well.