Just saw the highlights on Sky. Lund's try was bizarre; the Saints clearance was charged down, and he was clearly a metre in front the Sale player who touched it, nevertheless, he picked the ball up, but then stopped. Reihana, who was running to tackle him also stopped and everyone was looking at the ref for him to blow up. When he said play on, Lund practically walked over while Saints wondered what was going on.
It may have been a borderline decision from where the ref was standing, but it was clear on the TV (and to the players). I don't see why the TMO can't be used in this situation (considering the game was on Sky). Only using the video replay in the in-goal area is a strange quirk of union law at the minute, and it has often been influential (i.e. Howley's try in the Heineken Cup Final for Wasps V Toulouse, when the ball bounced on the touchline before the try was scored).