Question re: exchange zone disqualification

[UNIgiantslayers]

Not even sure if anyone will read this based on the mileage on this board but here goes:

What is the rule on contact between runners from other teams within exchange zones? Specifically, the following situation.

4x800 relay, state meet. Runner A2 hands to A3. A2 then stops in lane 1. B2 hands to B3 who then collides with A2 in lane 1 following the exchange. B3 is clearly put at a disadvantage because of the collision. Is there a rule justification for a dq here? I quickly perused the NFHS book, but I'm not handy enough with it to find anything that would back that up.