I've flown CX regularly for a few years, and never had any issues with overbooking. However on a recent flight from Oz to Frankfurt, both the HKG-FRA and return legs were overbooked.

Travelling in a group of 25 it was a real problem when part of the group were unable to get on the flight to FRA, especially as we departed Frankfurt immediately on arrival.

I've heard (not experienced) stories of airlines in the US offering compensation for pax volunteering to take an alternate flight, however CX did not mention the problem to anyone checking in until they started to bump people, hence someone that may have been willing to spend an extra day in HK never had the chance.

There were apparently up to 20 pax bumped from the flight. Out of interest does this sound like normal CX policy, or more like an issue with an earlier flight??

FWIW we checked in for the late night flight at the airport, so would have been well back in the checkin queue compared to those that did so online or downtown - but I'm sure many tour groups would do the same thing.