grammar - Why does 「電話は切れた」 sound more adversarial than 「電話が 切れた」?

I noticed that while 「…、電話が切れた」 sounds just like a neutral phrase ("... and the call got cut off."), 「…、電話は切れた」 sounds more like you were negatively affected / that the person on the other side intentionally cut off the call.

1. Are there any other examples where changing が→は causes something similar?


2. Is there a grammatical explanation for why this is the case?

Example 1

This is the sentence which first made me think this:

「そうですか。わかりました。失礼します！」
一方的に三浦は吐き捨てて、電話は切れた。

_{池井戸潤『空飛ぶタイヤ（上）』、講談社文庫、p. 353}

I felt that は flowed marginally better here -- my initial thought was that it's because it was an adversarial situation, but perhaps it's for another reason.

Example 2

After some Google searching, I found a document which actually includes both phrases, and I think it's interesting:

大分市内在住 82 歳男性宅に、「7 月分の高額療養費の支 給が 35,000 円ある。手続きは今日まで。お客様番号を伝 えるので、保健所に電話するように。お客様番号は 998-573」との電話があった。不審に思い「市役所に出 向けばよいのか？」と聞くと電話は切れた。

vs

平成２４年１０月１１日午後、大分市に住む７８歳（女 性）の被保険者宅に、支所の職員を名乗る男から電話がか かり「保険料の還付が３万円程度ある。８月に緑色の封筒 で通知を送っているが見たか？」と尋ねられた。また番号 （９９８７４５）を告げられ、これをメモに控えようとし た被保険者が何回か聞き返しているうちに電話が切れた。

To me, the first passage seems to feel like the call was cut in response to the question, while the second passage is more like the call just cuts at that point in time (as opposed to being initiated by a human in response to something).