Geez, I had a Deathclaw Matriarch sneak up behind me and attack me while I was ransacking some raiders.
Thank god for game exploits....inventory opened and I popped: Aspirin, Buffout, Ibuprofen, Psycho, Jet, Night Ghoul Eye, Tribal Healing Powder and Stimpak.
I was a walking pharmacy, couldn't see straight (pretty colors, though) and used up six or seven clips from a Tommy Gun, but she did go down in the end.
That was scary. Though so was losing track of a Sentry Bot the other day.
i started a new character recently, currently lvl 4. i was in the super duper mart doing the quest for moira. i clear it of raiders (took a bit of time) and find the quest stuff. as i'm heading out, another raider tags me in the back with a sledge. i thought it was odd, but didn't think anything of it. i continue toward the front of the store, only to find that a new batch of raiders have spawned in their usual locations. the bodies of the other raiders remained as well.
i'm not sure why this happened, as i was in the cell when it spawned the 2nd batch of raiders.
i also got completely mauled by 2 enclave soldiers + 2 talon mercs when i fast traveled to that farm near the SD mart (same savegame -- on the way to do the stuff for moira). i'm not sure if MMM can cause this, but it svcks having to run from those guys armed only with a couple of small guns and a few grenades.
Are you sure the first one wasn't the scripted second batch of raiders that spawns when you open the medicine chest?
And the second one kinda sounds like a random encounter from fast travelling.