Honestly, said sounds a lot better to me in that example. There's nothing about the word said that would negate the intensity of the dialogue. Said is like a blank slate, it just means to make an utterance. Which could mean making an utterance of any sort, from what I gather.

"Look out!" John yelled seems redundant because the reader likely already figured out that the character is probably yelling, then the author tells them they're yelling. This might feel to the reader like the author didn't trust then to figure it out on their own, like the article said.

But, personally I feel like that would actually be the best time to use a gesture to support the dialogue rather than an attribution. John is probably not just standing stock still. Is he reaching out a hand to pull his companion out of danger? Ducking so he doesn't get smacked in the face by the whatsit he is warning them about? I feel like a gesture would paint a much clearer picture.

Just my two cents (which may have turned into something more like a dime. Oops.).

"Look out!" Jack ducked under the fence and grabbed the little girl just as the runaway rhinoceros hurtled past.

A lot of the time, the tags are unnecessary anyway.

But yeah, somewhere someone pointed out that actual descriptions - yelled, whispered, mumbled - are useful quite a lot. Commanded, decreed, protested, and waffled are much less so, and should be conveyed through the dialogue. Heck, you can probably match them up to the following lines easily, even with no context:

"Take her to the brig."
"You can't lock me up!"
"You have endangered every person on this ship; you will be confined until we reach port."
"Actually, Captain, according to the regulations, specifically section VII part 8 subheading a.ii.kappa, as revised in the third quarter of last year..."

The reason you'd need anything other than straight dialogue there is to highlight that line 4 is a third speaker. But you definitely don't need dialogue tags.

hS