It would seem that 9 has inherited 5th's poor Tardis piloting skills. Arriving at Rose's home, the Powel Estate, the Doctor and she face the facts that they have arrived a whole year late! The matter is soon smoothed out with the police, whom the Doctor and Rose simply tell them that she was employed as his traveling companion. With Jackie furious and mistrusting of him, the Doctor decides to take his mind off the matter by investigating the mystery spaceship that crahsed through Big Ben and into the Thames. A forth noting note for this episode is the Doctor meets Torchwood 3's Toshiko Sato, posing as a doctor since her colleage, Owen Harper, had a serious hangover and couldn't do the 'Space Pig' optopsy.
Since the Doctor has had previous meetings with unit in his 2nd,3rd,and 4th incarnations, he knows their battle protocals, since if anyone else was confused as to why he knew what formation to tell the soilders to take up when Tosh screamed after the pig got out of its optopsy holding cell.
Its hard to beleive the Slitheen know human terms and what the person they skin for thier skin was like; i mean it would be pretty hard to assimulate into someones lif unless you were watching them for some time in order to take it over, like a stalker.