When Captain Archer travels to Brazil, Hoshi Sato is teaching a class in another language. The closed captions state it is Klingon, however, since Earth hasn't had any contact with Quon'os before, it is highly unlikely they would know how to speak it, Hoshi tried to use the universal translator when Klaang is in sickbay. Since she wasn't familiar with any Klingon dialects, with the small sample the Vulcans donated, the language she was teaching was another species, possibly insectoid.
Captain Archer mentions that a "7 foot" Klingon would be hard to miss on Rigel 10. In Star Trek, the metric system is used, therefore his height would be referenced in meters and not feet. Also, Klaang is only 6"5.
Shortly after departure, Captain Archer states they will arrive at Kronos is ~80 hours. He later states they are traveling at 30 million km/s. That is 100x the speed of light, which means they would be traveling at just above warp 4.6, though he was likely stating an approximation, and they were actually traveling slightly slower. However, even at 30 million km/s, they would only travel ~0.91 light-years in 80 hours, which wouldn't even get them to our nearest star, Alpha Centauri (4.367 light-years away). It would take 16 days just to get there at that speed.
T'pol describes the planet Rigel as being "approximately 15 light years from [their] current position." After the Enterprise travels to the planet, Captain Archer describes Klaang as having been on Rigel "just a few days ago," but even at the then-maximum rated speed of the Enterprise engines, Warp 5 (214 x light speed), it would have taken the ship about 26 days to travel to the planet, making the Klingon's meeting a month or more in the past by the time they arrived.
Star Trek has often been inconsistent regarding the ability to go to warp within a star system. Doctrine in Star Trek: Deep Space Nine says it can't be done. However in Star Trek the Original Series and the TOS movies, they routinely went to warp inside the solar system, most notably in Star Trek III: The Search for Spock. It is highly illogical that Kirk and Archer could routinely go to warp inside solar systems, and apparently the later presumably more advanced star ships could not.