It is a field study with a real environment and real situation so it has high validity.
Care was taken to make sure that witness testimony never altered what actually happened so the findings seem reliable.
We cannot generalise from the findings because only 13 people took part so it is not representative of all people. Also it has been suggested that they were looking at flashbulb memories which is different to lab experiments so they cannot generalise the findings to criticise the laboratory work.
Scoring turned qualitative data into quantitative data but there might have been bias with subjective interpretation of the qualitative data.