Yup, got yelled at by a random rider today, and yes I deserved it.
Was out my my usual 3hr training ride, and cranking along, things were going fine. I was working pretty hard trying to keep my power up, and getting more than a bit tired at the last hour, but holding steady.
More than a few times, had to slow for other slower riders who are hugging the left side of the shoulder so you can't pass on the left if there's any traffic on the road. Most of the time I can get by no problem, but at least twice, had to slow to literally 50% of speed to wait for cars to pass before making the left-pass, and this is out of courtesy as the right shoulder was really big on these sections (like 4 cyclists side by side could fit) but I know from experience that people tend to yell if you pass fast on the right even with all that space.
Came on the final mini-climb - an short, approx 300m incline of about 8-10% but which has a busy right sided freeway exit smack at the top of it. Because of that freeway exit, I try to hammer this climb and get up and over it ASAP - there are always cars waiting for you to get by, and some of them are impatient. Today there happened to be another rider on this same miniclimb, near the top, but I was probably going over 2x her speed as I approached. Again, she was totally hugging the left, and since the exit lane was to the right, I figured I'd make the pass on the right (lots of cars on the left 40mph) right when I hit the exit ramp (using the exit ramp as an extra-large shoulder of sorts.)
Unfortunately, and not unexpectedly, she started going right at the same time as my pass, and even though I felt there was a lot of room (we weren't close to contact and she was going maybe 6mph), I def startled her, and she gave me the "WTF are you doing!?!" I sheepishly waved and said "SORRY MY BAD!!" twice, but Im' pretty sure she's still fuming now.
So I def deserved that one, but at the same time, I do wish riders who aren't on the speedier side shouldn't hug the left aspect of the shoulder or bike lane, forcing anyone to pass way into traffic, when there's ample room on the right. Unfortunately, riding on the left does seem to be the norm, and I'm def not passing on the right anymore, no matter how clear that pass on the right looks.