I’ve used that intersection literally thousands of times. I never noticed a problem with the west turn onto Southgate, either for cars or pedestrians.
Thousands of cars go through there a day; Even if a near-miss occurred there once a week, the odds of any individual driver noticing are pretty low. And i'm not saying there ever was an issue, just that the previous layout was less safe than a standard intersection, with the bizarre lane line markings and the set-back sidewalk. They don't typically put custom warning signs telling drivers to watch for pedestrians at every intersection, so the fact that one was placed there is pretty strong (albeit circumstantial) evidence that there is / was an issue there.
Having turning and through traffic in the same lane just adds to the confusion. You don’t know what the car behind the turner is going to do so you have to make a quick decision whether to pull into the roundabout or not. You then have a similar choice re the northbound traffic. They might yield or they might not. Do you want to bet your life on defending your right of way?
Aside from the fact that the car behind the turner should also be signaling if they are turning, the car in front is slowing down to make the turn; this provides the gap. This only works if the car behind the turner can't go around, because they are in the same lane. Previously, no gap would have been there.
There shouldn't have to be a decision re: northbound traffic for a vehicle turning left off Southgate. Northbound traffic should always yield to traffic in the roundabout. There is no excuse for a driver not to yield; there is multiple signs ahead warning the driver.... roundabouts are not new anymore and are pretty common, if someone doesn't know how they work by now, why are they still driving? For traffic operations to work, drivers have to assume others will drive somewhat according to the rules, stopping at yield / stop / red lights and so on.
The good news is, it's not 'betting your life', it's at most betting your car's paint job.... the speeds are very low (30km/h or less) and any impact is at an angle, not head-on / T-bone so any damage is much less. That's one of the key safety features of a roundabout, far fewer severe collisions.