Assalamu allaicum wa rahamtullah wa barakatuhu
Dear brother "Korai_28" I agree with you that we should always give proofs when we ascribe certain things to someone or to a particular group, because we must always bear in mind that what we say or do, directly or indirectly, we are createing or we are haveing impact on how someone will interpret our words tomorrow and which message he will convey to others.
But I also believe that the intentions of our brother were directed towards good, and that everything he said was for the sake of Allah and our benefit. On this path we can all make mistakes, but what is important is that we always need to have nice opinion about each others, to advise each other on nice and kind way, as it is in the spirit of Islam and its teachings. At the end we should correct each other mistakes on the same way, because only with kindness and kind word we can reach out to others.
We need to show with our deeds and words that we sincerely care for our Ummah, for our brothers and sister, we must not allow for our brotherhood to be "alive" only in our words, and to have our deeds going in completaly different direction. To your brother or sister in Islam you need to give them their rights, and among those rights are love for them, support, advice, and this is exactly what Islam teaches us and what is emphasized in many places in the Quran and then in Sunnah of Prophet Mohammed s.a.w.s., but sadly today is being brought in question, not in a sense that we do not know for our obligation towards our brothers and sisters, but in a sense that we do not apply it in our daily life, or we do apply it but very little.
Allah says in the Qur'an:'Believers are indeed brothers so reconcile your brothers.'(Al-Hujurat: 10)
"Prophet Muhammad (peace and blessings be upon him) said: 'You will not enter Paradise until you have faith, and you will not have faith until you love each other. Shall I direct you to something which if you fulfill you will love one another? Spread peace among yourselves.' (Muslim)
Finally we have a duty toward Allah, to follow and spread Islam, to convey the message of Islam and its teachings, not only to non-Muslims, but Muslims who may for various reasons, and Allah knows best, make some mistakes, which can be corrected only with our help and our support, and most importantly with gudience of Allah.
And Allah knows the best
Wa Allaicumu Sallam wa rahamtullah wa baraktuhu