"Without it, the entire sentence would be a comma splice, with Tom saying the word that follows ‘Tom said,’ rather than describing how he said it, Tom said, pontifically.
“Tom didn’t say ‘Tom said pontifically.’ Tom said it, pontifically,” like the bishop to the actress.
“Ah, but every grammar site I’ve checked finds that ‘Tom said swiftly’ is correct, and that ‘Tom said, swiftly’ is incorrect”, replied the Professor additionally.
“I’ll have an American cheese sandwich on white bread, and then the vanilla pudding,” Tom said blandly.
Any cites, either way, are difficult to impossible to find. Where did you see that? Finally, after a zillion pages of whether commas go inside or outside closing quotes, I used as the search terms
comma quote “attribution at end”
and found this, along with the usual comma-inside, comma-outside suspects, Tom didn’t say, much like the dog in the night time.
“I’m Catholic and I think I’m gonna die,” Tom said unctuously.
“My pet frog died,” Tom croaked.
“Here’s one for starters: Do All Adverbs End in ‘-Ly’?”, the Professor said hurriedly.
“I’m not one of those guys who wants a big wedding”, said Tom, unceremoniously.
“Here are two more:
the adverbs modify the verbs,” the Professor added obviously.
“That Pepperwinkle is really on the ball”, Tom professed.
“What would happen if I hung all the way out the window?” asked Tom sillily.
I see nothing in any of your links that addresses attribution following a quotation and nothing addressing comma splices after a quote or the sentence fragment that results.
“I am great, M4 is great,” Tom said happily. = “I am great, M4 is great,” Tom said green. Then he said red and yellow.
Whether the attribution contains an adverb or any other part of speech is immaterial. Tom isn’t saying the attribution, unless you want him to by leaving out the comma, at which point it would still look like an error. The only way to prevent him saying it instead of describing how he is saying it is with a comma. Oh yeah: Tom said.
"Wiki says: 'Comma splices are condemned in The Elements of Style, a popular American English style guide by E.B. White and William Strunk, Jr.
According to Joanne Buckley, comma splices often arise when writers use conjunctive adverbs to separate two independent clauses instead of using a coordinating conjunction. A coordinating conjunction is one of the seven words: for, and, nor, but, or, yet, so. A conjunctive adverb is a word like furthermore, however, or moreover. A conjunctive adverb and a comma (or a conjunctive adverb between two commas) is not strong enough to separate two independent clauses and creates a comma splice. For example, “There is no admission fee, however you will be responsible for any food you order,” contains a comma splice with a conjunctive adverb. Only semicolons and periods are strong enough to separate two independent clauses without a conjunction.
Grammarians disagree as to whether a comma splice also constitutes a run-on sentence. Some run-on sentence definitions include comma splices, but others limit the term to independent clauses that are joined without punctuation, thereby excluding comma splices.’ and since the end adverb is not a conjunctive adverb, and does not constitute an additive clause by itself, the comma is omited," referenced the Professor, aware this was taking all the fun out of the game.
Please start another thread if you want to discuss that further. This is a thread for Tom Swifties. Thanks!
“I really like this brand of sandpaper,” Tom said coarsely.
“My anti-gravity belt stopped working when I was 100 feet up,” Tom said, flatly.
“I’m something of a cat person,” Tom said doggedly.
“But I also like dogs,” Tom said cattily.
“I’m more of a bird person,” Tom tweeted.
“I shouldn’t have mooned the pub,” Tom said, embarrassed.
“It’s Ash Wednesday again”, Tom said, relentlessly.