I've asked this question earlier on the boards, and the answer I received was that if Diving Tackle is used to effect a Dodge roll, the -2 penalty will still remain even if the dodge is then rerolled and Diving Tackle has already been declared for the original roll. However, there was some legitimate confusion about this between our leaguemates recently, as the way the rules are written do seem to introduce needless ambiguity:
The interpretation some of the members made was that this wording suggested that Diving Tackle could be used on the first roll OR on a reroll, but presumably would not affect more than a single throw of the die. Given the odd wording of the rule that explicitly notes it may be used on a rerolled dodge IF NOT declared for the first Dodge roll, this alternative interpretation seems reasonable to me.... The opposing player must subtract 2 from his Dodge roll for leaving the player's tackle zone. ... Diving Tackle may be used on a rerolled dodge if not declared for use on the first Dodge roll. ...
Is there any text in the rules or FAQs that clarify this ambiguity, or is it just the dominant convention of the community? I'm assuming it has something to do with all modifiers in place being preserved during rerolls, but couldn't find anything in the book with another quick look.
Thanks!