Where I must disagree with you (and the New Fowler’s if it condones it) is using “me” in a compound subject: “Me and Dave are going to the pub.”

You may do it deliberately as “a matter of register,” but many speakers do it because they don’t know any better.

My five-year-old granddaughter says “Me and my daddy went to the park,” and “Me and my mommy painted a picture.” She doesn’t do it for the sake of register. She does it because one of her parents does it in every context.

When an educated speaker like you says “Me and Dave are going to the pub,” an uneducated listener cannot be blamed for imagining that the construction must be acceptable English. I think that it’s possible to speak informally without departing from standard grammatical usage. (http://www.dailywritingtips.com/colloquial-does-not-have-to-equate-with-ignorant/)

What’s more, I can’t think of an occasion where I’d ever say – ‘At least we know it wasn’t she that killed Cara’ – it may be ‘correct’, if you believe that only formal English is correct, which I don’t – but it doesn’t sound at all natural to me.

I wish that people (for example PreciseEdit) would stop castigating those of us, who like me rarely use ‘whom’ and would never say ‘Hi mum, it is I’, as being uneducated or ignorant. We know the choices very well, and prefer to speak natural English rather than the artificial version cooked up by the traditionalists. A position supported by dictionaries such as Merriam-Webster.

It’s about time we all realised that formal English is the exception, not the ‘rule’. Grammar should be based on common educated usage, not on the whims of grammarians trying to fit English to the rules of Latin.

And perhaps before pontificating about what is ‘correct’ and ‘incorrect’ about things like the use of the word ‘data’, it might be a good idea to check with a dictionary.

Talking of dictionaries – Oxford Advanced Learner’s Dictionary – ‘veg out’, phrasal verb.

This occurs in other areas of language use, too. For example, “Data,” which is a plural term, is often used with a singular pronoun and verb. To many, this sounds correct, though it isn’t. Wrong: The data is in the report. Correct: The data are in the report.

We concede that spoken English isn’t as formal (in most situations) as written English. However if more people used English correctly, especially those in the public, in the media, etc., people in general would likely be inclined to do the same.

This is an issue we encounter at every training session and with most documents we edit. Several articles in the Precise Edit Training Manual address the difference between what sounds correct and what is actually correct. (FYI: We’re donating $1 to the National Center for Family Literacy for every manual purchase through December 31. This organization has much work to do, obviously!)

Corrected:
My mom and I used to go there.

The examples given:
She and him were sneaking around behind my back.
At least we know it wasn’t her that killed Cara.

The examples corrected:
She and he were sneaking around behind my back.
At least we know it wasn’t she that killed Cara.

If the corrected forms are too “inauthentic” sounding for TV characters, a scriptwriter could get around them with variations that would still be couched in correct grammar.

Variations”
My best friend was sneaking around behind my back with my boyfriend. Or
They were sneaking around…

At least we know it wasn’t Suzy that killed Cara.