“...was hit by the ball being thrown to first.”
If you check the video, late in it, you will see that Jackson leaned into the throw enough that his left leg came off the ground and caused the interference obviously intentionally.
https://www.youtube.com/watch?v=tvWKWvrVfrI
(4) Any member or members of the offensive team stand or
gather around any base to which a runner is advancing, to
confuse, hinder or add to the difficulty of the fielders.
Such runner shall be declared out for the interference of
his teammate or teammates;
(5) Any batter or runner who has just been put out, or any
runner who has just scored, hinders or impedes any following play being made on a runner. Such runner shall be declared out for the interference of his teammate
http://mlb.mlb.com/documents/0/8/0/268272080/2018_Official_Baseball_Rules.pdf
Page 61
wy69
Side note on Jackson: while in college a group of us went to an Angels game, sitting by the RF foul pole. Jackson, then a Yankee was the right fielder, hitting an even .300
He struck out in his first AB. When returned to his position we started a chant: 299….299! …..299!!!
Second at bat was a repeat: 298!!! ….298!!!!
Third AB: Home Run
He returns to his spot and turns towards us and shouts: 27!!!
He had us!