The official results noted ICR rule 628.7 for the reason for disqualification - "requests a re-run which proves not to be valid."
In effect, the skier said he was interfered with in the first run (bib 5), requested and was granted a re-run. (Ran between 15 and 16).
The Jury (3 persons) then received a protest (against granting the re-run) from the Finnish team.
After video review, the jury must have concluded the athlete had no grounds for the re-run - as Yuki noted, because he didn't stop at the point of interference (or, they perceived there was no interference) his re-run was invalid.
It is unclear when the protest was filed with the Jury - when time allows, first run protests are generally handled prior to the second run - in this case, TV feed created a time constraint and the athlete was allowed to ski the second run. (the second run was still 15 minutes later than scheduled on the program).
Check out the FIS ICR
- the International Competition Rules for Alpine Racing.
As far as the course workers, yep it's always a dicey situation. The start interval between racers was 1 minute 40 sec for the first group - in Slalom, there is no start interval, but at the World Cup level, it is determined for media purposes - the live TV feed to Europe.
The course workers make every effort to maintain the racing line to be as fair from one athlete to the next. The snow conditions generated rutty conditions early - much more work. In defense, go run around on a steep, slippery slope without ski boots on with tools in hand and inevitably a butt check by a course worker is gonna happen. The course worker in question was NOT in the racer's line - the distraction was the excuse used to initially justify the re-run request, after the athlete fell further down the course.
Bottom line - safety IS the number one concern of the race jury at this (and hopefully all) levels.