What is the validity of inferring the purity of khamr (wine/intoxicants) from the fact that the Prophet did not forbid pouring it into the streets of Medina when it was prohibited, nor did he order the washing of the vessels from which it was poured?

According to the majority of scholars, Khamr (intoxicant/wine) is ritually impure (najis), based on the verse: {O you who have believed, indeed, intoxicants, gambling, [sacrificing on] stone altars [to other than Allah], and divining arrows are but defilement from the work of Satan} and on the Hadith of Abu Tha'labah concerning the washing of vessels in which Khamr was drunk. Imam al-Nawawi explained that the strongest evidence for its impurity is the severe prohibition and deterrence against it, by analogy with the impurity of dogs. As for the Companions pouring Khamr in the streets, this does not indicate its purity, as it is possible they were unaware of its impurity, or they poured it on the sides of the roads. Furthermore, the Prophet's command (peace be upon him) to pour it out was in a garden, not the street. In conclusion, this issue is a matter of scholarly disagreement, and each side has its evidence.