I believe everything stated in the article is correct and very well explained. Now, it is not completly true to say that specific memories cannot be "erased". Roger Pitman has found that giving Propanalol can impair memory formation in a person that just experience an event that would very likely turn into a traumatic memory. That would be messing with consolidation of the memory. But he has also shown that this drug has the same effects on reconsolidation of memory. He dosed PTSD patients with prop as they were recalling the traumaic experience, and in the next session, they suffered less stress when recalling that same event.

Effect of post-retrieval propranolol on psychophysiologic responding during subsequent script-driven traumatic imagery in post-traumatic stress disorder.