The genius who gets the credit partakes as well in illusion and error. It remains to posterity to conveniently overlook these and to remold his achievements so that they form a suitable basis for modern dogma.
Case in point: Lavoisier. He himself stressed the principle of logical progression. In his preface to the ELEMENTS, he laments that "Imagination" can lead us into "deceiving ourselves" and notes that as a consequence, "... in the science of physics in general, man have often made suppostions instead of forming conclusions." He resolves to do better, stating, "We must trust to nothing but facts : These are presented to us by Nature, and cannot decieve."
Au contraire, mon frere! He goes on to advance several errors as fact: That acids contain a universal "acidic substance" and that heat is a substance.
Recognition of these sorts of imperfections only make his achievements all the more impressive, just as in the case of Galileo, who drew many wrong conclusions.
Lavoisier’s errors you mentioned were not entirely unfounded. His contention that what made an acid was universally oxygen. At the same time, English scientists asserted that acids universally contained hydrogen. They were correct.
In practice, Lavoisier’s was not an unreasonable assumption, as the great majority of common acids at the time contained oxygen, and because it is such a noteworthy and reactive and reductive ion. Only with the later discovery of hydrochloric acid did it become plainly clear that oxygen was not the essential characteristic of acids.
His other incorrect assumption, that heat was a substance, was likely due to an entirely new state of matter unknown at the time: plasma.
Plasma can most definitely act like a substance, which would lend itself to the impression that heat, not the invisible plasma, was exerting pressure. This would appear to be the case in Lavoisier’s time. Proof that heat was not a substance would be very difficult.