Large inaccuracies with Ruby Geocoder and/or OpenStreetMap - openstreetmap

Question

I'm using the geocoder gem in rails to get latitude & longitude for addresses and then display them in OpenStreetMap.
When I search for my old address:
>> results = Geocoder.search("1000 Mount Curve Ave E, Altadena, CA 91001")
I get:
>> results.first.coordinates
=> [34.1976645, -118.1278219]
Mount Curve Address Discrepancy
Those coordinates are perhaps a thousand feet off. (See image.) The resulting accurate coordinates from Google Maps are [34.200503,-118.1310407].
I've tried another address and it was much farther off, perhaps a mile. (1346 E Woodbury Rd, Pasadena, CA 91104)
I've tried yet another address, and it was pretty much dead-accurate. (922 E Brockton Ave, Redlands, CA 92374)
Does anyone know what might be causing these inaccuracies and how to get accurate results consistently?

Answer 1

Because of the inaccuracies and/or limitations with OSM/Nominatim, I switched to Google maps service. At the top of my controller I added:
require 'google_maps_service'
And in my controller's show routine I ended up with this, which yields accurate results:
source = Property.find(params[:id])
#property = PropertyDecorator.new(source)
gmaps = GoogleMapsService::Client.new(key: '[removed, put in your own key here]')
results = gmaps.geocode("#{#property.address1} #{#property.address2}")
if results[0] == nil
#lat = 0
#lng = 0
else
#lat = results[0][:geometry][:location][:lat]
#lng = results[0][:geometry][:location][:lng]
end