If you mean "it's to be expected that X happened" or "it's unsurprising that X happened", say so.. Don't say its "Understandable that X happened"...
Understandable means that you empathize with the action, or sympathize with it, or can find it reasonable, or excusable, or justifiable... or at least understand and find reasonable that others might.. If that's what you mean, then OK... that's what you mean. But if it isn't, then use the right words and constructions to convey the right meaning.
This isn't just meaningless wonkery... it's a very important distinction.
Definitions matter. Words matter. Communication depends on these things. Misunderstanding and conflict are generated and perpetuated based on getting them wrong.
