Because an uncooperative Bruce Willis refused to re-record several lines of dialogue when the movie was being restructured, a sound-alike voice-over actor had to be brought in.
During the opening montage showing the development of the surrogates, there is a shot of an Asian man with an android twin. This is actually footage of Dr. Hiroshi Ishiguro of Osaka University and his creation -- Geminoid, a prototype android double of himself.
The weapon appears to be based on an ozone generator -- with a bunch of added parts to make it look more exotic and weapon-like.
The film takes place in 2017.
A close-up shot of Strickland's FBI file shows his date of birth as December 21, 1969, and birthplace as Lynn, Massachusetts. These are also the real date of birth and birthplace of actor Jack Noseworthy, who plays Strickland.