The logic is not based upon one player. It is for all games. This just shows it does work. Most players home records are superior, more so when Gilly played.
Tendulkar - Home 48, Away 37.
Lara - Home: 44, Away 38.
Kallis - Home 47, Away: 41.
Sangakkara - Home 41, Away 43.
Ponting - Home: ave 39, Away: ave 45.
Symonds - Home 29, Away 43.
Hussey - Home 47, Away 51.
Hayden - Home 39, Away 43.
These were the first four non-Australian batsmen and first four Australian batsmen of Gilchrist's era that came to mind. Sangakkara is the only non-Australian batsman who averaged more away than at home. But Tendulkar, Lara and Kallis all averaged significantly better at home than away. And all of Gilchrist's contemporaries in the Australian setup averaged more away than at home.
I didn't realise that the discrepancy was that bad, but even the "home track bully" Hayden averaged significantly more away than he did at home in ODI cricket.
Though this isn't taking into account neutral venues.
I guess it goes to show that playing in Australia as an ODI batsman isn't as easy as it is in other, smaller venues. The MCG, Gabba, SCG and Adelaide Oval all have quite large boundaries on at least one axis (the AO has small square boundaries but long straight boundaries) which gives something for the fielding team to work with when trying to cut off the 4s and 6s.
So yes, Gilchrist's average is almost exactly 36 and Dhoni's average is a bit over 50, which is significant. But when you take into account the roles that they played in their respective teams and the conditions in which they played, the gap between the two is nowhere near as large as it looks on paper (for the record, Dhoni's home and away is 55 and 49).