Right. Now i've picked out Jonathan's post about there is no 'reply to thread' option from the hybrid view, so i should be replying to that as it is the only one in my browser.
I have '+Reply to Thread' in the bottom left-hand side highlighted in blue. I thought this meant that i would be replying to the main post in the thread, however it functions exactly the same as the 'reply' button - it replies as Shewie says to the last post in the thread.
I have clicked on the 'reply' button. Now i am going to 'post quick reply' which should post this reply in the hybrid view directly to Jonathan's post.