It is fine to say Einstein is wrong to refer to views he expressed in his body of work. This is known as literary present tense, and is widely used in academic writing and literary criticism. Here is a piece of advice from Harvard University:
Whether you are dealing with fiction, poetry, or nonfiction literature, use the present tense (also called the literary present tense) to discuss the actions and thoughts presented in the text. Do this because literature exists as a present phenomenon regardless of whether or not its author is alive.
Here are some examples (my emphasis):
Aristotle conceives of ethical theory as a field distinct from the theoretical sciences. (…) Aristotle follows Socrates and Plato in taking the virtues to be central to a well-lived life. Like Plato, he regards the ethical virtues (justice, courage, temperance and so on) as complex rational, emotional and social skills. [Stanford Encyclopedia of Philosophy.]
But because he [Rudyard Kipling] identifies himself with the official class, he does possess one thing which ‘enlightened’ people seldom or never possess, and that is a sense of responsibility. [George Orwell, Rudyard Kipling, 1942, six years after Kipling’s death.]
[E]ven I, with my tiny knowledge of both fields, can catch Kipling out on the bull-fight and on naval gunnery. He is wrong about the manufacture of liqueurs, too. [Kingsley Amis, Rudyard Kipling and His World, Thames and Hudson, 1975, p. 81, quoted in The International Fiction Review, 1977.]
The literary present tense is used mostly in nonfiction writing, but you can find it in fiction occasionally too:
Shakespeare says something about worms, or it may be giants or beetles, turning if you tread on them too severely. [R. Kipling, ‘His Wedded Wife’ in Plain Tales from the Hills, 1888.]
Shakespeare alludes to the pleasure of watching an Engineer being shelled by his own Battery. [R. Kipling, ‘Watches of the Night’ in Plain Tales from the Hills, 1888.]
Shakspeare alludes is a favourite with writers. It is used a lot more often than Shakespeare alluded (see n gram). And people have commented on Einstein (1879-1955) in this way too:
As Kiley indicates, Einstein is undoubtedly a realist. [J. F. Kiley, Einstein and Aquinas, Springer, 1969, p. XIX.]
Einstein believes there is an intrinsic order within the physical world, which exists outside of man. [Robert K. Logan, The Poetry of Physics and the Physics of Poetry, World Scientific, 2010, p. 209.]
So suppose Tarantino has been affirming this view of Einstein’s, and you disagree. Then you could say:
Einstein believes there is an intrinsic order within the physical world, which exists outside of man. Tarantino believes it too. Well, Einstein and Tarantino are wrong.
It would be different if you were thinking about something they did on a particular occasion. Then you would use the past tense. For instance:
Einstein and Tarantino both predicted it would rain on their 18th birthdays. It didn’t: they were both wrong.