Worst case scenario for any bottom lane specifically because the death could have been avoided. 
Annie, filling the role of Support has a sight ward in the river bush which later provides vision on Amumu charging down the lane. Annie pings Graves to retreat and begins to back off to the tower.
Caitlyn, knowing Amumu will be in range shortly is moving up in the lane so that Graves cannot easily get out of her range. Janna also moves forward to provide additional CC on their target.
Graves, believes he has an opportunity to get some damage in on Caitlyn as it appears she is unknowingly moving into his range. He jumps out of the brush with Quickdraw, lands Buckshot.
Janna shields some of the damage from Buckshot and knocks up Graves. Amumu is now in range and lands his Bandage Toss due to the knockup and adds more damage with Tantrum.
Graves now realizing he is in trouble tries to retreat. However from the damage he is taking from Caitlyn and Amumu, along with all of the CC he was locked down with, he quickly dies before getting getting past the brush he was initially in.
- ↑ Source: Actual In-Game Experience, this particular scenario being observed while I was taking a red buff.