Is it true that putting a long stock sale as short on form 8949 only matters if the result is a loss?

I went to H&R Block so I could meet with a person of supposed knowledge which I regret. 298 shares of a stock. 48 were sold short. The other 250 were long. She lumped them all under short. When I questioned this her response makes no sense to me. It was
“The sale doesn't really matter about long or short term, but I will change it if you want me to. It would really only matter if the results were a loss”