As far as I can tell, that's mostly not what the study says. What it is saying is that the event of a judicial election and the pressures associated therewith demonstrably cause systemic disadvantage to defendants and appellants near election time, but it doesn't actually address how the overall rulings of elected judges compare to appointed judges except for one study it mentions that does say, in your defense, that they [elected judges] reverse death sentences less often in the states that have the death penalty. However it goes on to say:

These studies leave open several important research questions. For example, they generally do not compare systems, and thus do not address whether some re-election or retention election systems have more of an impact on criminal justice outcomes than others, or whether reappointment processes may also have an effect.

And later says:

Much of the empirical research considering the impact of judicial selection dynamics on criminal justice outcomes has focused on elections. Further study is needed to understand the incentive structures created by appointive systems, particularly those that provide for reappointment. The few studies that have considered these dynamics suggest there may be reasons for concern.

For example, in one such study, Joanna Shepherd examined how the political preferences of those determining whether to extend a judge’s tenure impact judicial decision-making. Just as the public’s preferences may impact case outcomes within electoral systems, Shepherd found that the preferences of governors can have a similar effect in states where they play a role in reappointing judges. 92 Indeed, Shepherd determined that as governorships change hands, so too do judicial rulings; when a Republican governor replaces a Democratic governor, judges’ rulings in a variety of cases, including criminal cases, shift.93 Shepherd’s findings suggest that reselection pressures are a concern even outside the election context, and highlight the need for further inquiry into the dynamics of appointive systems.

And that's really the full extent to which it addresses the subject of appointment.