But I have noticed many times when I posted in the forum post box I forget to put back button pressure
"Back button pressure", what could that possibly mean? That you click the return key on your device and it takes you back to the previous page? If that's your point, I get screwed most time like that so I can relate.
But I did not understand how a post was submitted twice.
There's no point of making the emphasis, it doesn't happen that way. If you accidentally submit a post twice, then it has to be on the same topic.
[...] especially since both posts are made in same day in short time difference..
Since this a notepad story, unless it's been happening already before now, I think it might have been a mistake as well.