It will be complicate to afford in the few lines of a post the Pinetti-Decremps relationships.
It is true that Decremps never named his rival: this was the typical style of his time literary tradition of the caustic and satyric pamphlets; also to avoid legal problems or give free publicity to his target.
The evidence of Pinetti is however given by the textual and precisely allusive coincidences in the chronology between Decremps' Magie Blanche Devoile (1784), Pinetti's Amusements Phisiques (May 1784) and Decremps' subsequent Supplement a la Magie Blanche Devoile (1785). And is only in this latter work that Decremps uses the Pilserer character. In his first text, Decremps just speaks about "a famous italian having glory everywhere". Anyway, f you read carefully the three books (especially in French), you understands clearly how Pinetti is clearly Decremps' target. Other proofs are in the contemporary press and playbills.
I'm not sure about Robert-Houdin's sources about Pinetti: but at his times allusions and reference were in the sources of early Paris theatrical life, in some dictionary, or scarce books about magic, especially in the ones agains charlatanism. For exemple, Pinetti is among the subjects of Abb Fiard two books of 1803 (La France tromp par les magiciens) and 1815 (Le mystre des magnetizerurs....). It is also possible that Robert-Houdin found other sources about Pinetti when performing in London, where Pinetti left quite some traces (his Haymarket playbill and programs are still remaining).
If you read French, I consider interesting two books with references about Pinetti and Decremps: Campardon's seminal Les Spectacle de la Foire (1877) and recently reprinted) and Fournel's Le Vieux Paris (1865).
I briefly afford the subyect in my book Illusionismi (2002) that is in Italian language, and some most extensive recent French sources are available too.
I hope having been helpful
If you like magic history, you can find amusing my blog: www.raffaelederitis.blogspot.com