"Accidental Interference"

[harmbu]

FED rules. R1 with one out. Ground ball to F4. He throws to F6 to force the runner at second. As F6 is making the throw to F3 there is contact between him and the sliding runner. The throw is late and BR is safe. After the play is over, I ask for time and ask if the contact was beyond the base. He says, "Coach, what I have here is accitental interference." This term sounded foreign to me so I ask what he means. He says "Hold on. I will talk with my partner." He goes to his partner and comes back and says the contact way not beyond the base. I accept this and return to the dugout. When I got home that night, I decided to try to figure out what he meant. I got my book out and could not find the term "accidental interference" anywhere. Can anyone explain?