Much caution is required when reporting these issues.
This article touches on two distinctly different areas. One is the 'analyst accused of tampering with evidence' and the second is ' bias and sloppy work'. By my interpretation, one is a crime and the other is not (subject to any bias being unintentional).
Linking the two different scenarios into one article is not helpful to either circumstance, as each warrants healthy community discussion.
The overarching issue is a management one. There must be measures in place to minimise the opportunity for evidence tampering ..... and there must be measures in place to ensure the scientific validity of the examination and reported opinions presented.
The discussion on bias is well documented in forensic science disciplines. Sloppy work is a fascinating term but a management issue to eliminate.