[quote name='The Holy Pretzle']I think that after a certain number of retries, the game throws you back to the checkpoint you had before the one you have now. I remember this happening to me in Nightfall with the shade turrets and after I was trying to get "If They Came to Hear Me Beg" on the last mission. I jumped off a cliff trying to assassinate the Elite, then after a certain number of respawns it threw me to the very beginning.[/QUOTE]
It must be a lot of retries. There were parts of the levels on my legendary playthrough where I must have died about 30 times in one area.
BTW I finally got "if they came to hear me beg" yesterday. It took me probably a good 20-30 minutes of trying it over and over, but I eventually got the achievement to pop, even though I had done multiple assassinations already. FWIW, I did it on normal difficulty, and hit myself with a grenade to hurt me before I fell. Not sure what it was about that one particular attempt that triggered it, as I had done assassinations from the air before, also when being hurt, etc. Maybe I just happened to be in the right position finally. For those having trouble, just keep trying it's gotta happen for you sometime!