The whole Barry has anger issues thing feels out of nowhere, none of this was present in the first season.
Barry was generally calm, cool and collected when killing people, always based on pure logic and not rage.
His emotional issues used to be about dealing with the fact that he is a cold blooded killer.
Then we get the whole story from his past and it turns out that the story is about how he killed an innocent man and the event that led to him being discharged.
How could he ever think of that event as "the time I saved a life" like he stated earlier and then go "oh right, that was THAT time".
And how could he equate killing a guy in rage after your friend was shot in a war setting to killing Moss?
Its nowhere near the same thing, but this one I can see being on purpose. Barry wanting so bad to not be seen as a bad guy that he is reaching here to draw these kind of absurd conclusions on his way to a reality check later in the season makes sense.
I love this show but this episode was very disappointing.