That was us x That were us: Qual a forma correta?

Eu estava assistindo ao episódio 10 da 2a temporada de The Vampire Diaries, e a tia da Elena falou (no minuto 2) "That was us". Não seria "That were us"? (qual delas os falantes nativos usam?)
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Avatar do usuário PPAULO 40955 6 32 717
Okay, I have to elaborate when a bit when giving the answer, it´s not a sucint one, I´m afraid.

“Who said the Pound was moving on fundamentals this week? Oh, yes, that was us. We were wrong, the pound is back moving on political headlines,” says Kathleen Brooks at City Index.

Who said? Oh, yes that was us.

Both his parents were undocumented when they came to the United States. For health care, they relied on home remedies or drove three hours across the border to Tijuana if someone fell ill, he said.

“And it’s still happening,” he said. “People forgo care because they can’t either afford the drugs or to pay for it. That was us.”


Who (had to forgo) care because they can´t either afford or to pay for it? That was us.

But he does not accept accusations that his government treated residents insensitively after the announcement. He said the government bought potentially affected land during the consultation process and before federal approval purely out of compassion. ‘That was us trying to bend over backwards to say to people, "If you're stressed out of your mind by this thing, we'll buy your property." That wasn't well understood, but that was actually us being extraordinarily sympathetic to the local people.'

That was us - let´s think of it as a way to answer "who" has done something (in the past or in recent past), and that "who" could be one people/intitution or several ones.

We began as a country where we were willing and able to cross a frozen river, at night, to kill our enemies, in their sleep, on Christmas. Yes, that was us. We did that. Now, do you want some of us?

I like this last one, it answers your question superbly. That is, "that was us" is the same as "we did that". :-) Usually, for emphasis, when asnwering a question or a question that we ourselves haves just made to somebody else.
Of course, it´s just the chunk "that was us." nothing else.

For instance, in the following chunk of text that part doesn´t have the same grammatical value, so the rule of plural with "s" applies.
He wanted to reunite his country, and he wanted to kick out the foreigners that were us.
Avatar do usuário PPAULO 40955 6 32 717
Notice that here it´s not a short answer following a question (just made), as was the case before.
He wanted to reunite his country, and he wanted to kick out the foreigners that were us.