^^ I believe if you look more closely, you will find that that 'white area' is on the rudder shaft rather than on the hull - the lower part of the shaft which turns/rubs on the lower bearing.
It is possible that the shaft has dropped down a couple cm's from its normal position, and that is why so much white us showing. That would indicate some damage to the shaft and associated hardware
But The rudder is quite 'stable' and not moving in the sort of way that I would expect if the shaft was broken and detached from its upper bearing inside the boat. For me at least, that indicates that the head of the shaft was probably not broken off. And that the 'failure to steer with emergency rudder' was either due to the autopilot/quadrant being jammed inside the boat, or the crew simply finding it much more effort to use the emergency tiller than they expected. You should not ever count on a typical bilge
pump to bail you out of a below waterline breach - you need a serious crash pump for that.
There is also no sign of the mythical pot/trap. So far I see no sign that this was caused by any outside influence, rather was simply a failure of a boat system - either the autopilot failed and broke the rudder seals
or one of the other systems (I listed above) failed and shorted out the autopilot as a side effect of flooding the boat.
As an aside - in a collision
(or torquing) with an external object, like a log, usually the damage to the shaft is right at the bottom of the lower bearing, and the rudder snaps right off and is gone.
I agree with you about bailing by bucket.
As a further aside . . . it is eye opening for anyone who cares to examine how ineffective typical bilge
pumps are in an emergency situation. They can handle very slow weep and random condensation
and rain down the mast
. . . but are entirely unable to keep up with a significant below waterline breach. The cooling
water circuit is also not a very high volume pump. Just for some quick numbers - a 2" hole 2' below the waterline will flood 113 gallon/min. The very largest Rule
bilge pump (and most boats have bilge pumps significantly smaller than this) will pump 36 gallons/minute against a (typical) 6.7' head. And a 75hp yanmar
running flat out pumps 14g/minute of cooling water. On the other hand, a 2" crash pump will move 175 gal/minute against a 7' head - they are also much more impervious to (the almost certain) debris in the water than the typical bilge pump or engine cooling pump - but most boats don't carry these.