I couldn't find another Robert Christian "of German" (presentments) in the 1851 census, which was the closest to the date.
In the 1851 German census there is a Robert Christian b.Maughold living in Poortown with wife Agnes and small child, next door to Philip Barr & family (prob Margaret Boyd's son - Margt Barr's brother). And with Wades on the other side.
See the 1851 census for Robert Christian and family (on this BB - previous message) to compare.
This looks like the same route the Auckland Christian family took with their information which they sent to Bob.

Sue