No, but it demonstrates that Fate Core expects players to be proposing "Event" compels before Narrative Action is even taking place in a scene, that is, during framing.
Well, there's "expects" as in "I am prepared for this to happen" and there expects as in, "this is really central to function, and failing to do so is a problem". The situation for the game is more the former than the latter.
Players can suggest compels. Period. The game tries its best to not get in the way of that, so it allows them to come just at framing, during the scene, or retroactively. If characters are going to do cool stuff, the Fate points must flow. So, stand back and give folks opportunities.
The GM proposes his first "hook" and the players suggest modifications that are effectively retroactive "event" compels.
In practice, in my experience, doesn't happen much. The game allows for it, but the players generally look to the GM to frame the scene, in fairly traditional manner.
Complications to the characters life don't have to be the result of compels, they can just happen. Changing it to the snake makes it a viable compel on the snakes aspect:
Correct. You may get a Fate point not just when your situation gets more complicated, but when it does so in a manner that is thematically appropriate for the character, specifically. Which is to say, is a complication in line with your specific aspects.