Today (Sunday 10th May 2009) they published that doctors
expect her to make a full recovery.
They also said she does not remember anything from
the incident, including the cause for her drowning.

They also published what you hypothesized:
It is very easy to release the feet from any type of
tie to the boat, including the shoe/boat assembly you mentioned,
therefore they do not know what caused the accident.
They did not publish, and maybe they don't know,
if the boat actually capsized, or just sank
without turning upside down.

Erez

: Many racing shells have lightweight shoes screwed into the footrest of the
: shell. Rower enters the boat barefoot and inserts his/her feet into the
: shoes, then laces them. This provides the most stable platform for pushing
: with your legs - the 60% of power in sliding-seat rowing.
: In the story you describe the most likely scenario was as follows: -She
: entered the shell, attached her feet to the footrest, either with the
: screwed-in shoes or the more generic foot-straps.
: -During the workout something caused her to capsize. In rowing capsizes, as
: in: "the boat upside down" are VERY rare. The riggers and oars
: act as natural "paddle floats", thus naturally preventing the
: boat from capsizing.
: In my 6 years of rowing I was swimming many times, but never capsized.
: The oar may have broken loose from the oarlock or she may have fainted [heart
: attack!?], thus entirely losing the balance and control of the boat.
: -I suspect she fainted or otherwise became unconscious. Even being upside
: down, a young, fit, strong rower on flat and calm water could easily free
: herself from the footrest.
: -You know the rest of the story...