Having endured only the latest round of unflattering reviews following the deadly building collapse at 22d and Market Streets in 2013, Philadelphia's Department of Licenses and Inspections should be approaching its crucial and daunting task with that much more care and caution. That is not the impression left by the revelation that hundreds of inspections were conducted by trainees who lacked required credentials.

About 600 inspections conducted one week last month were performed by newly hired, uncertified employees but recorded under the name of a single experienced inspector, The Inquirer's Alfred Lubrano reported Monday. Ironically, the 600 inspections took place the week that City Controller Alan Butkovitz's office issued a report reiterating some familiar and pertinent criticisms of L&I - namely, that it suffers from insufficient staffing and poor record-keeping.

Nutter administration officials say the inspections were part of a training exercise and wholly unrelated to the controller's report. They maintain that the new employees were qualified to conduct the inspections, having passed the relevant exam, even though they had not obtained final certification by submitting necessary forms and fees. They note that the senior inspector's name appeared on all the reports because he led the training and had access to the department's database. And they say the 600 inspections involved only 203 properties and a limited set of previously discovered problems, making the work achievable within a week.

Current and former L&I employees told The Inquirer that the inspections were a gross departure from standard procedures that would leave the department legally vulnerable to the kind of unscrupulous property owners who have tended to run circles around the city. But L&I Commissioner Carlton Williams blamed the criticism on "individuals in the department and outside who are having a difficult time adjusting to the reforms we are implementing. . . . Unfortunately, some want to go back to a situation prior to the terrible tragedy at 22d and Market, to a time when there was less oversight of dangerous conditions than there should have been."

Granted, departures from past practice are often desirable, especially in a department with L&I's checkered history. And the Nutter administration's welcome if gradual efforts to reform and fortify the department are bound to cause turmoil in the ranks.

But in an agency tasked with getting the details right - and often contending with landlords who have excelled at exploiting the bureaucracy's every weakness - there is no room for doubt about who inspected what, much less whether he or she had the necessary credentials. That could be the unintended lesson of this particular training exercise.