Such as firing the FBI official who refused to comply...
The firing is a valid concern. But directors have been fired before. Could be many reasons.
Trump stated it was due to the Russia investigation in the CNN interview the next day.
And whether or not it harmed the investigation is irrelevant, the question is whether the intent was to harm the investigation. So given that
1. Trump asks comey to stop the investigation 2. Comey doesn't 3. Trump fires Comey 4. Trump claims that Comey was fired because of the russia/flynn investigation
I don't see how you can read this any other way.
1. Trump asks Comey to stop the investigation because it's creating bad press and is undermining the goals of his administration
2. Comey doesn't
3. Trump fires Comey for disloyalty and for allowing what Trump sees as a distraction to worsen, not because he believes the firing will somehow end the investigation.
4. What you said, though specifically because Comey's actions showed disloyalty and created problems for administration vs an effort to deliberately "obstruct justice"