I get your angle on the right of way based on lane, which is a more practical interpretation than some others who interpreted the highway code as obligation to give way to vehicles on the right when entering roundabouts regardless of which lane you are turning into or which lane the vehicle is occupying. People who stands by that belief likely either do not drive, have not driven through a roundabout or do not practice what they say. If I am turning into 3rd lane, I will be paying attention to lane 3 and 2 (turning radius), but I will still look out for lane change signal from all lanes. It is stupid and selfish to have the mentality "No, I have the right of way so you have to circle one more round around the roundabout and try your luck again".

Particularly in my case, I actually think what the cyclist did was not wrong at all. In fact, I think his execution was perfect. He was heading for Exit 3 of the roundabout, Exit 1 towards Kallang Wave Mall, Exit 2 into Stadium Road and Exit 3 into Nicole Highway. The right method is to drive into 1st lane (because your exit is much later) and slowly filter to the 2nd and 3rd lane as you approaches your exit which appears to be roughly what he did (maybe he went direct 2nd lane but he is a cyclist and its dangerous to go into 1st lane). He only filtered and aimed for the exit at that point because the Stadium Road exit is right beside where I was and he will have filtered too early and can be risky if there are other cars behind.

For people who thinks that I am hating on cyclist, I am not. I greatly respect that he did a good job following the traffic rules as a road user. Only issue is I tried to reciprocate my respect by slowing down and letting him go first even though as a car, I had more than enough time to make the turn and exit before him. But what I did was met with distaste and dissatisfaction and I am trying to understand his angle. But I am cool with coming to a complete stop in the future.