Hi :)
I don't really know who is Ernest Pinard and what his réquisitoire is but I can help you find arguments from Les Fleurs du Mal because I have studied it in class for a while
Basically, Les Fleurs du Mal was considered really controversial and modern because Baudelaire transformed "bad things" into beautiful poems, which was the opposite of the Platonic tradition (tradition platonicienne) which said that beauty was necessarily assosciated with good. So yeah, it was really audacious to do that at the time and Baudelaire quite succeed !
By the way, my teacher told us that transforming "bad" or common things into something "great" can be called "alchimie poétique" (poetic alchemy) because the goal of alchemy was to transform things (like mud or lead) into gold.
Unfortunetaly I don't have the book with me right know be we can pretty easily find example of poems to illustrate that .
Also, he uses a lot of analogies such as metaphors, allegories and other stylistic devices (I don't know if it's how to say "figures de style" :/ ).
One part of the book is called "Tableaux parisiens" (=parisian paintings) so it kinda compare his poetry, full of imagery and considered beautiful, to painting. So that emphasises the aesthetic side of Baudelaire's poetry.
Hope it kinda helps and sorry for my english