"These are innocent people Eiji! We could save them!" - Sonic
"You don't get to talk about saving people ... WHEN YOU'VE MURDERED MINE!" - Eiji
"I already told you! Eggman set a trap! I didn't know your people were in there!" - Sonic
"Bullshit!" - Eiji
"Eiji-" - Sonic
"DON'T FUCKING TOUCH ME!" - Eiji
>>•<<
More Sonic verse Eiji.
In this universe they're really angry and upset over the destruction of their people. So, as a result, they tend to unintentionally lash out at people that don't deserve it.
Or in this case, someone they believe to be the cause of their peoples' death. Eiji eventually does learn the cause of their peoples' death was actually because of Eggman. For now, there's unwanted tension/rivalry between them and Sonic.
Takes place somewhere in book one, Sonic Chronicles: It Has Begun.