Ok, so we've said that anytime uke gets flaky and starts doing unexpected things, one great way to improve your chances of remaining safe is to get a hand in his face as a strike or a separator. There are only about three relationships in which this is possible, those being shomen, aigamae, and gyakugamae. These are the three fundamental atemi in aikido. The other two atemiwaza are responses, or "what ifs" related to those first three atemi.
Aigamae is the "same stance" in which tori and uke each have the same side forward. in this relationship when tori is outside uke's arm, aigamae ate happens. Gyakugamae is the "opposite stance" in which one partner has right side forward and the other partner has left side forward. From this relationship, when tori is outside uke's arm, gyakugamae ate happens.
It is important in all three of these atemiwaza to realize that striking makes for bad throws. This is because when tori strikes, her arm recoils and she loses contact with uke. With tori only having contact with uke for an instant it is difficult to for her to exert significant control over uke. Therefore, pushes are better controls than strikes. With gyakugamae it is particularly tempting for tori to push or strike uke sideways. This is also bad mechanically. The proper gyakugamae pushes forward through uke's head then follows uke's head downward.