Your right! 

Its  not only pest vs. cholera but also grandmaster brain vs. amateur brain - with 35...Kg8 Sutovsky made Svidler work whereas with my move the game would have finished much earlier. (Mental notice: dont make obvious moves without thinking  )

Improve your rook endgames - here is Svidler-Sutovsky (some analysis are given in e4e5-section by GM Flear) from the position of the diagram:

35. Rf5+ Kg8 36. Rd5 Rb1+ 37. Ke2 Rb2+ 38. Kf1 Rb1+ 39. Ke2 Rb2+ 40. Kf3 Rd2 41. h4 Kf7 42. Rd7+ Kf6 43. g3 h5 44. Rd5 g6 45. Ke4 Rxf2 46. Kxd4 Rf3 47. Rg5 Rc3 48. Kd5 Kf7 49. Kd4 Kf6 50. a4 Rxb3 51. Kc4 Rb1 52. a5 b3 53. Kc3 Kf7 54. Rb5 Rg1 55. a6 Ra1 56. Rb6 g5
57. hxg5 Rg1 58. a7 Ra1 59. Rb7+ Kg6 60. Kb2 Ra6 61. Rb6+ Rxb6 62. a8=Q

35...Ke7 seems more logical than 35...Kg8.  From e7, I suppose the black king could harass the rook on d5 (...Ke6).  Although this might offer more resistance, it doesn't look like a critical decision to me.  The passed d-pawn is Black's only trump in this position, but he can't prevent it from falling.  It looks like a difficult ending for Black to hold in any event.

However, I can't see any reason to actually prefer 35...Kg8.  It's an odd looking move (at least to my eye).