The bias can be made negligent by mandating a certain format to the report (some Google insider has to provide this detail) and due to the fact that multiple such reports go into the decision-making.

As an example no words which might create a impression but sticking to facts. The inference is left to the second panel. For example instead of saying the candidate thought hard about the given problem say something like the candidate tried out 3 different solutions to the problem over the interview time period. The first panel are merely conveyors of Data; so their reports have to be detailed and to the point.