These statements purport to refer to an extended but unified historical thing, the French Revolution. This thing is assigned a place within a causal system, being caused by one set of factors and having causal consequences for other factors. It is considered a suitable topic for comparison with other such things (the Russian Revolution).
But what does the historical reality of the French Revolution consist in? Notice, to begin, that the revolution comprises a huge constellation of events and actions, both small and large. Were any of these events "the definitive moment" in the revolution--the decisive event that constituted the constellation as a revolution rather than a "period of unrest"? Is it possible to distinguish clearly between core events and peripheral, minor events--not to speak of events that are wholly unrelated to the revolution? Most radically, would it be possible to construct the events of 1789 in such a way that no revolution occurred at all?
One possible answer to these questions is to reply that the events directly associated with the overthrow of the monarchy and the establishment of a different form of political power constituted the essence of the revolution. But what if later historians were to conclude that the transfer of power was illusory, and that the same interests in society continued to govern? In fact, if the monarchy had been restored in 1830 we might reasonably say that "no revolution occurred, only an interruption of monarchy." Would either of these possibilities represent a refiguring of the historical picture in which the seizure of power is minor and background rather than major and foreground? And would this not be a basis for doubting that "a revolution occrred in 1789"?
It seems best to understand "the French Revolution" as an intellectual construction--one possible way of knitting together the congeries of events that occurred during this time in France. Some constructions of these facts are more plausible than others, so it is possible to have rational dispute about the alternative construals of the constellation of events. But there is no essential fact of the matter that a revolution occurred in France in 1789. This doesn't derogate the status or facticity of the constituent events. But it does assert that the historian's act of composing events and actions into a large historical structure is an act of construction rather than recognition.