Sorry about the slight echo, but I think the audio is still clear enough to show what I mean. I'm using JLAB to practice listening comprehension, & in the first clip, "hitori" sounds exactly like "hitun". I've replayed it over & over, but I can't hear any other pronunciation. In the second clip, "konoatari" sounds a bit like "konoatan" to me; in this case, I think I'm starting to hear the "ri", but it's still rather unclear.
This kind of issue has been occurring often enough that I can't tell if my ears are playing tricks or if certain characters possess some mystical dialect. That first clip is especially strange because there's no way that character isn't saying "hitun".
The thing is, there was probably some quality control over the dubbing of those anime, so a bonafide Japanese speaker must've listened & thought, "Yeah, this sounds right." However, personally, some words sound so unrecognizable that I don't even know if they're slang.