Meaning of らしたのじゃありません?


Prior to this sentence, Kawashima was talking about jumping from the school's
roof with Obata-sensei; aftwerwards, another teacher is speaking with Obata,
and says:

> 小幡先生はひょっとして、自習時間に川島さんが話していたことを小耳に挟んで、だから不安になって **らしたのじゃありません** ？

I'm guessing the `不安になってらした` means "became worried/uneasy", but I can't
understand what's `らした`'s meaning.

Also, is `じゃありません?` like `じゃないか`, so like asking "isn't it?" rather than
denying? So the whole sentence sounds like "During the free study period you
happened to hear Kawashima speaking, so you became worried, isn't it?".

I'm having quite some difficult following this story so I'm not sure: on one
hand it sounds right, on the other Obata did hear Kawashima - Obata didn't
just happened to hear, Kawashima was speaking directly with Obata. It could be
a roundabout way to say Obata knows what Kawashima said, but I'm not sure.




らした is a less formal, contracted form of いらした, which is a [variant of
いらっしゃった](https://japanese.stackexchange.com/q/29805/5010). Here the meaning is
the same as 不安になって **い** らしたのでは or 不安になっていらっしゃったのでは.

And this じゃありません is indeed like "..., didn't you?" or "It's that ～, isn't
it?". Put together:

> ...だから不安になってらしたのじゃありません？  
>  ...and thus you got worried, didn't you? / right?




らした is a less formal, contracted form of いらした, which is a [variant of
いらっしゃった](https://japanese.stackexchange.com/q/29805/5010). Here the meaning is
the same as 不安になって **い** らしたのでは or 不安になっていらっしゃったのでは.

And this じゃありません is indeed like "..., didn't you?" or "It's that ～, isn't
it?". Put together:

> ...だから不安になってらしたのじゃありません？  
>  ...and thus you got worried, didn't you? / right?

