Who DID NOT VOTE on yesterday's EU Withdrawal Bill?

The 634 MPs who did part in the vote are listed here by They Work For You:
https://www.theyworkforyou.com/debates/?id=2019-01-15a.1020.0#g1121.0

But 16 didn’t. Of those, half of them would not be expected to vote: the Speaker, John Bercow, plus the seven Sinn Fein MPs who do not take their seats in Parliament, on principle (Órfhlaith Begley, Mickey Brady, Michelle Gildernew, Chris Hazzard, Elisha McCallion, Paul Maskey and Francie Molloy).

That leaves eight MPs who might have voted but for whatever reason did not:

Conservative MPs:

Iain Stewart (Milton Keynes South)
Eleanor Laing (Epping Forest)
Wendy Morton (Aldridge-Brownhills)
Labour MPs:

Paul Flynn (Newport West)
Vicky Foxcroft (Lewisham Deptford)
Lindsay Hoyle (Chorley)
Nick Smith (Blaenau Gwent)
Rosie Winterton (Doncaster Central)

… I’m curious as to why they missed the biggest defeat of the Government ever.
(data correlated with Wikipedia lists of current MPs)