IMHO, a good rule of thumb
: If the contact would be considered a PF during a live ball, then treat it as a DBPF, if the contact was incidental after BUT THE WORDS WERE NOT = USC.
EXAMPLES :
(1) 2 players bump as they unpile and head back to their huddles = nothing, it's a contact sport.
(2) 2 players bump and one responds : "Your grandma is a 'spud-chucker'" = potato thrower, slang in some portions of Maine = USC.
(3) 1 player grabs another by the baby-makers = DBPF, and toss if felt necessary. Player
may need to register as a sex offender
depending on local statutes.