When on the conversation with Niko from the restaurant, the position of Erik's pen switches from the table on the "real" scene, to his right hand on the displayed scene in the ship.
The technique used by Salvare to slingshot around the star makes no sense. The purpose of the sling shot maneuver is to increase the speed of your ship above your current speed using the gravity of another object. There's little point in reducing your speed to sub-light (William dropped them to sub-light before awakening Niko) so that you can sling shot to back to the +light speed you were traveling at in the first place. Not to mention the fact that the sling shot maneuver is not accomplished by getting as close to a star as you can, nor are multiple orbits around the star beneficial. While this error might be forgivable there nothing gained by using an incorrect procedure when the correct one could have them arrive at the same plot point.
When discussing the slingshot technique with the computer guy, William, it was stated that they would be going sub-light speed. I.e., they had been traveling for a month faster than the speed of light. And, Sirius is over 8 light years away. So they are then going to share instantaneous transmissions and communications with Earth which cannot travel faster than light? At least Star Trek was careful enough to have Warp Drive and transmissions via "sub-space."
When approaching Sirus A, Niko and William can be seen standing in the transparent cockpit of the ship, perpendicularly to its axis.
If artificial gravity was available on the ship, it would be either radial (in the external ring, by rotation) or parallel to the axis (due to the acceleration of the ship), not perpendicular.
When the alien artifact suddenly blasts a recording of Mozart's Eine Kleine Nachtmusik, it is apparently so loud that we see three characters cover their ears with their hands, wincing in pain. However, two of the characters take their hands away from the ears right before the music ends.
Their interstellar ship uses schedule 40 pipes for plumbing.