Well, IMHO, they do not need to interview the tower controllers.
The recording transcripts from the ATC are available (the ones used in the report, hence can be used as evidence), if they know where to look. It was already circulating around by the first weekend after the accident. The information was also signed, and therefore a legal document.
But again, whether it would be enough for the investigation to go to court, I dunno.
How long would you have after touchdown to decide "there's not enough runway to stop" and could you still initiate a go-around?
Between the time you touchdown and the time the reversers are deployed. After reversers are deployed, don't count on Lady Luck to give you a safe go-around... her job is to give you luck until reversers... *grin*
PK-KAR