#showtooltip Steady Shot
/castrandom [target=pettarget,exists] Kill Command
/castsequence reset=2/target !Auto Shot, Steady Shot
/script UIErrorsFrame:Clear();
First off the reset=2/target is what might be messing it up
Second, didn't they get rid of the ! function since some hunters were cheating and double aimed shotting?
Third, you probably want your reset to be 3 seconds, not 2.
This is what mine looks like:
#showtooltip Steady Shot
/script UIErrorsFrame:Hide()
/castsequence reset=3 Steady Shot, Auto Shot
/cast [exists,target=pettarget] Kill Command
/script UIErrorsFrame:Clear(); UIErrorsFrame:Show()