right, because there the "were" applies to affidavits, which is clearly plural

It's a singulare tantum, according to the plurale tantum Wikipedia page.

One of our salesmanagers pages for "2 available sales personnel"

okay, yes--I now think it is a collective noun, and thus can take a singular or plural verb depending on the context and sentence structure.

Glad to know everyone's paying attention in class this morning! Just to mess you up, here's another excerpt:

there is a scintilla of evidence that limitations was tolled . . .

and in this case "limitations" is singular, because it's shorthand for "statute of limitations."

Doncha just love grammar?

The only evidence were the affidavits.
The only evidence was the affidavit.

Were/was depends on whether the object is singular or plural.

"The only evidence was the affidavits."
The affidavits were the only evidence.
I don't see why the sentences have to work the same both way round, you can have a subject in the singular and an object in the plural, or vice versa.
The only food left was five loaves.
The five loaves were the only food left.

"there is a scintilla of evidence that limitations was tolled . . . "
In this instance was is correct if everyone understands the jargon, that "limitations" is singular, because it's shorthand for "statute of limitations."

Dammit, made me go look it up...

So here's another explanation:

If I was If I were

From Wordwizard.com

So I'm wrong (above).

but that rule doesn't apply here though--this is not a case of the subjective tense. That rule applies to something like this:

"If I were to go on a cruise, I'd choose the Bahamas."

Or even subjunctive mood.

"subjunctive" yep. a bit subjective if you ask me . . .

It made me tense. ;)

Them there afferdavids was the only evidense

And now a joke:
A businessman from Boston had been away from his hometown for nearly 20 years and dearly missed the local seafood. On a trip back east he landed at Logan and was no sooner in a cab when he urgently told the driver "I MUST get Scrod!"
The cabbie turned to look at the man and said, "I've heard it said a lot of ways but never in the Past Pluperfect Subjunctive."

(lafs). and THAT is why we all love the English language so much!