What went through your mind and what you said are two clearly different things. You did not say "Let me know when he gets back, I have some suggestions for his design".

You can be as well-intentioned as you want. You can perceive the situation your way as much as you wish. However, when there is a discrepency between what you thought and what you actually said, do not blame us for not being mind readers who know what you meant to say.