Obstruction of justice is typically things like bribing witnesses, which is specifically mentioned in the law. Not refusing to unlock oa locked cell-phone, which the courts have held requires a warrant in other circumstances.
From the information in the article, this sounds like an attempt to scare a citizen into doing something.
Attempts to widen this particular law to cover less serious crimes get rejected by the courts: the very first case on the subject inCanII says (emphasis added)
 Moreover, an assertion that the mere attempt by an accused to identify an informant is a crime, fails to take into account that the types of conduct which constitute obstruction of justice, even though not fully articulated in the Criminal Code, are relatively well and narrowly defined in the law, and must remain so narrowly defined in order to have certainty in the law. Offences against the administration of justice have always included such conduct as attempting to influence a jury or to threaten a witness, or publishing sensitive information when a matter is working its way through the justice system, a general category of conduct which lawyers sometimes call an infraction of the sub judice rule. I have been unable to find a single suggestion anywhere in the law that an accused cannot take steps to identify a police informant; the court should act with restraint in opening new classes of obstruction of justice. Although obstruction of justice is an evolving concept, its main tendency is to narrow the categories of conduct which may constitute a crime rather than to enlarge them: Sunday Times. Recent examples of the narrowing of the categories include the removal of scandalizing the court as a matter of contempt, Kopyto, and the striking down of the publication ban on bail hearings, White.