Though from a similar background to Daniel Jackson, Robert tended to be more skeptical and not nearly as quick to consider extraordinary explanations to scientific puzzles. Despite being a decathlon champion in college, Rothman was often bogged down with frustration and self-defeat, and had a tendency to slow down others around him.
When SG-1 found a Crystal skull on the planet P7X-377 and Dr. Daniel Jackson disappeared, he and MSgt. Sylvester Siler were assigned to study it, but could not determine its function. (SG1: "Crystal Skull")
While on an archaeological dig with Dr. Daniel Jackson on P3X-888 (the original Goa'uld homeworld), Rothman witnessed the kidnapping of Jackson by Chaka. He managed to get back to Stargate Command where he informed Jack, Teal'c, Sam and Hammond of what had happened and also to get reinforcements. He returned with the rest of SG-1 and SG-2. At some point, during the night or morning, he became infested with a local Goa'uld symbiote. It clandestinely kept up the appearance of being Robert Rothman, but eventually made its move. Dr. Rothman succeed in shooting Major Michael Griff, and would have almost certainly killed the other SGC members but luckily Colonel Jack O'Neill intervened straightaway, shooting Rothman dead. It is presumed that like the other victims who had died in the line of duty, Rothman was given a decent burial. (SG1: "The First Ones")
In 1999, during one of Dr. Daniel Jackson's dreams, brought on by Sha're through Sha're/Amaunet's hand device, he believed that Rothman would take his place on SG-1 if he were to leave the Stargate Program. He also believed that if Rothman did take his place, Colonel Jack O'Neill would most certainly object. (SG1: "Forever in a Day") One of O'Neill's objections claimed that Rothman "slowed down the unit," to which Jackson countered that Rothman was a decathlon athlete, yet Rothman is seen using an inhaler in a later episode. (SG1: "The First Ones")