Most awful ideas, plans, products, services in business happen because nobody had the courage to speak against them.
It is a difficult thing to do when everybody is aligned. The risk (being excluded, being rejected, being fired) is just to big.
Many companies preach diversity of thought and the possibility to raise flags, very few though seek that with intention.
So next time try scheduling a meeting to collect issues. Send an invite to a workshop to identify risks and pitfalls. Have a chat with that experienced colleague to challenge your assumptions.