"Total pedestrian fatalities dropped from 49 in 2011 to 44 in 2012" [1] Singapores' population is ~5 million[wikipedia], so the odds of being killed by a car for the total population is ~0.00088%

For a comparison let's look at NYC, which has roughly double the population within City Limits (~8 million for NYC):

"From 2002 to 2006, 843 pedestrians were killed"[2] That's ~211 deaths per year. Making the percentage odds ~0.0026375%

So you're about 1/3 as likely to be hit and killed by a car in Singapore than NYC. That's fairly significant, but there are a couple things to point out. NYC does have a significantly higher population density and I would assume it has a higher amount of vehicle traffic.

I think overall while it's clearly less likely to be killed as a pedestrian in Singapore, I wouldn't exactly call it "rare". And while I'm no professional on Singapore, I don't know why you characterize Singapore as somewhere that doesn't have large roads or many vehicles (There are 965,192 vehicles in Singapore[1]). Also I don't think CCTV is nearly as ubiquitous as you think, from the few news articles I've read they probably only have a few thousand with more only starting to roll-out recently[3][4]. It's certainly not up to London standards, and I doubt even there ever single pedestrian death is caught by CCTV.

[1]http://driving-in-singapore.spf.gov.sg/services/driving_in_s...

[2]http://www.nyc.gov/html/dot/downloads/pdf/nyc_ped_safety_stu...

[3]http://www.safetrolley.com/latest-news/singapore-police-inst...

[4]http://www.asiaone.com/News/AsiaOne+News/Singapore/Story/A1S...