Pages 14-15 of the Fate Accelerated PDF says this about the Create an Advantage action:
If you're creating a new aspect or discovering an existing one:
* If you succeed with style: You create or discover the aspect, and you or an ally may invoke it twice for free. Usually you can't invoke the same aspect twice on the same roll, but this is an exception; success with style gives you a BIG advantage!
If you're trying to take advantage of an aspect you already know about:
* If you succeed with style: You get two free invocations on the aspect, which you can let an ally use, if you wish.
Emphasis mine. So all versions of Create an Advantage give you two free invokes when you succeed with style, but only the create/discover rules emphasize that you can use both of those on a single roll. It also establishes the general rule that you can't invoke the same aspect more than once per roll.
The rest of page 15 is a summary of the basic actions:
Create an Advantage when creating or discovering aspects:
* Succeed with Style: Create or discover the aspect, get two free invocations on it.
Create an Advantage on an aspect you already know about:
* Succeed with Style: Generate two free invocations on the aspect.
Here, there's no mention about whether you can use those two free invokes on one roll. The Quick Reference on page 44 has the exact same text except for adding page numbers.
Finally, there's the "Invoking Aspects" section on page 28:
Important: You can only invoke any aspect once on a given dice roll; you can’t spend a stack of fate points on one aspect and get a huge bonus from it. However, you can invoke several different aspects on the same roll. If you’re invoking an aspect to add a bonus or reroll your dice, wait until after you’ve rolled to do it. No sense spending a fate point if you don’t need to!
Free invocations: Sometimes you can invoke an aspect for free, without paying a fate point. If you create or discover an aspect through the create an advantage action, the first invocation on it (by you or an ally) is free (if you succeeded with style, you get two freebies).
Here it reiterates the general rule of one invoke per aspect per roll, followed immediately after with reiterating rules for free invokes. But it only mentions create/discover. Also, it's unclear to me whether the last parenthetical remark refers to earning two free invokes with one action (in which case it should refer to Create an Advantage in general) or being able to spend them both on one roll (which is an exception to the general rule written just before, so it should have been written more clearly).
Going by the rules as written, I see only one place in the entire book that allows invoking the same aspect more than once on a roll, even though the case where it should come up is mentioned multiple times. That's why I have to ask for clarification, "When can you invoke an aspect twice for free on the same roll?"