Whenever Kohlar is shown on the Klingon Battle Cruiser, his hair is straightened; on Voyager, Kohlar's hair is curly.
When Voyager and the Klingon ship are shown moving through space together, the stars behind them are moving past quickly even though they are not at warp speed. When at impulse, the ships do not move fast enough for the visual affect of stars hundreds of light years away to be moving past the ships.