I tend to feel that Sonic stories should have (more detailed the FFNet offers) 'version of reality' tag attached, there's so many contradictory media. This one is Sonic X. I never entirely took to it, but in the absence of new fics to read have been trying again with it and there's the occasional episode that could have been fab at twice the length and with a bit more depth. Season 1: Ep 5 "Cracking Knuckles" in the English dub was one such.
Yes, Knuckles was convinced of Sonic's bad faith way too easily - but it's only way too easy because Eggman's acting is scripted as terrible and it's too quick. The actual story Eggman spins about Sonic not wanting to go back is initially convincing - Sonic really does demonstrate an utter lack of urgency about getting back throughout the series to this point, and even in this episode the only reason Tail et al are caught is because Sonic's lolling about, and when he does arrive, his attempts to wind Knuckles up inadvertently corroborate a lot of what Eggman has claimed! Done over a longer time frame and a less OTT Eggman it'd have worked without making Knux look silly. So for the purposes of this fic I'm pretending it did...
Sonic watched Amy harangue Knuckles out of sight before returning to the group.
"Are you really just going to let him just walk off like that?" she demanded.
Sonic quirked an ear. "Amy, the day I have to let Knuckles do anything, we'll all be in trouble!"
"He attacked you! He helped Eggman! How can you not be mad?"
Sonic shrugged. "Too much effort."
Amy glowered and Sonic sighed slightly.
"Look, it's like I said to Chris over that chaos emerald the other week. He made a mistake - he fixed it - no biggie."
"No biggie?" It was a shriek and Sonic flattened his ears against his head. How to explain to Amy - so new to the fight against Eggman, so untouched by it, so confident that no matter what, Sonic would sail in to save the day at the last minute? How to explain that the bigger the things you tried to achieve the bigger the mistakes you were likely to make and the bigger the consequences?
He made mistakes, Knuckles made mistakes, they both fought like fury to fix them and afterwards they both had their own strategies to avoid dwelling on them. Sonic adopted a supremely confident -"all in the plan," "never doubted it," attitude. Knuckles ignored them, pressed resolutely on, never explained, never apologised.
"But he never even apologised," Amy protested as if on cue.
"Yeah well, when has Knuckles ever done manners?" Sonic shrugged again.
Neither of them did manners if he was honest. Or speeches. One of the few things they had in common was an unshakeable belief that actions spoke louder. Knuckles had known he was blowing up the robot in his own face and had done it anyway to fix the mistake he'd made. There wasn't anything really that words could add to that.
The eye contact when Sonic had leapt in to the same explosion to grab him was apology enough, if one was needed. The lack of surprise in Knuckles' face. The lack of any attempt to grab Sonic's arm himself. Calm confidence that Sonic would not let go. Stillness as a more effective declaration of repaired trust than any awkward words.
Sonic couldn't of course easily explain any of this without yet more words. Nor did he want to.
Amy was still not derailed in her indignation however.
"And he didn't say thank you!"
This time Sonic actually laughed. "Got a smile didn't we? I mean, that's like a round of applause and a shower of presents coming from Knuckles."
Apparently out of arguments, Amy gave a loud harumph and stalked off, for all the world as though it was Sonic who'd offended her sense of good manners.
"You know sometimes you two are just the same!" she snapped as a parting shot.
"Hey,"Sonic protested by reflex. "I resent that remark!"
But he didn't. Not really.