Logical answer is they put it on back to front!

To put it VERY simply. The bogie tilts toe down because the gear, when it is retracted, is actually angled slightly forwards due to the pivot piont not being in line with the aircraft axis.

The nose down tilt is such, that when the gear is retracted and stowed in the under-carriage bay, the bogie and wheels are parallel with the keel beam. Thus making the most efficient use of the space.

The reason the gear is designed like this is AFAIK due to pavement loading/weight distribution which became apparent later in the design of the aircraft and at a stage where a complete redesign was not possible.

Thanks, 23 posts in and we get a sensible explanation. :O

I suppose the real reason isn't immediately obvious because one tends to assume that, if a gear retracts sideway, the axis of rotation must be exactly parallel to the aircraft's longitudinal axis.

Summed up nicely in post #2.