This very much fits for Sammy. In an odd way, it's a gesture of compassion towards Charlie. Just no compassion for the dead.
As for Milo's death, I haven't seen anyone put my theory forward yet. I think if Jenny does hate Charlie over Milo's death, it will be because of the lack of interest zombies have for Charlie. Charlie will be on point for the group (using the new guy to find traps by stepping into them is military tradition, right?), with Milo behind him, and an ambushing Hunter or similar zombie will ignore Charlie, remaining undetected till Milo comes by and it springs on him.
Thus, Milo dead, Charlie not actually at fault but plenty of room for Jenny to blame him.