how is it that two different scientist can make similar observations about a scientific investigation of phenomena and yet come up with different inferences

Because, regardless of what the observation was, the different testing methods were used and by different scientists there are different types of method, and what more, as people are different, will be different experiences, and this will result in Different results, because everyone has different views, scientists would not be different.

This may be because the two scientists experimented with different methodologies.

Explanation:

As we know, through the scientific method, a scientific conclusion only occurs after a few steps, the first being observation, which is the stage in which the scientist observes a particular matter or phenomenon. Two different scientists may make the same observation about a phenomenon, but that does not mean that their experiments would be the same and bring the same conclusions.

After observation, scientists may adopt entirely different methodologies to pursue their scientific experiments. The methodology directly interferes with the conclusion, so two different scientists can make similar observations about a scientific investigation of phenomena and yet present different inferences.