I am guessing that if the overs dominate again this week, regardless of reason, that unders will be the way to go the week following, because a) opening lines will be adjusted upward again and b) more people will recognize the trend and blindly bet the overs.
Also, my guess is certain types of defenses will be hurt more by this than others. If you can identify which are which, then there will be some opportunities there because invariably ALL lines will be adjusted, even if it's not always relevant because of the teams involved. For example, playing against a team that runs a lot, the effect should be less noticeable because those big hits happen a lot on pass attempts. In addition, inaccurate passers are more likely to see their team benefit because the punishment won't be as severe for those WRs.