... and to follow up on Demetrios' points as to why Herodotos could have gotten the incident all wrong with regards to Amompharetos. Not only was he speaking (and writing) for a mainly Athenian audience, from what I could gather his main sources for the Persian War were Athenian veterans, and most likely not particularly high ranking ones (one exception is the Plataian Arimnestos, who some scholars speculate was a major witness for both Plataia and Marathon). They could have pieced together some things they witnessed along with rumors, and of course the prejudices of the rank and file working to further modify their stories.
In a fictional account I have written about the battle, I transformed the event into one in which Amompharetos tosses the stone as a way of mocking Athenian democratic indecision.
As Demetrios pointed out, it would have been totally out of character for Spartan officers to be arguing publicly during such a critical moment.