There is a debate as to whether one can recite Hallel with a beracha on Yom Haaztmaut (related).
I have been to a synagogue where they had invited someone who is of the opinion that one should say a beracha and asked the community to answer amen. This is so that the congregation do not say the beracha itself, but are answering to someone who does hold by saying the beracha.
Is this contradictory? Or is it desirable, since you don't say the beracha yourself, but merely answer? Or is answering akin to saying the beracha itself and one shouldn't even answer amen if you hold by not saying the beracha?