Update:
Commute this AM was grand. No chainy issues at all.
On the PM commute however, 2 mins after leaving the office I slowed for some lights, which subsequently changed, I stamped down to get a quick getaway and next thing I know I'm still in the same place and my chain is getting acquainted with Tarmac.
Surprisingly (or not) it had snapped in a totally different place to either of the existing power links and and instead of a snap through the side plate as per last night, the pin had just pulled straight out.
?