Your numbers are wrong.
BR has Bradley at 19/4/2.5 in 35 minutes of action. Improved production likely mostly attributable to increased minutes. Also, this shooting percentage is probably not sustainable.
While your numbers are correct (should also be noted that Bradley is shooting 71% on FT, not in the 60s for the month), it's a bit of a stretch to say that AB's other numbers are due solely to an extra four minutes of playing time, as he's doing better on a per-minute rate for both assists and steals than he has for the year, as wel as turning the ball over less. It certainly could be a random month, but increased minutes does not account for the numbers (if anything, the improved production accounts for the increased minutes).
It's also a stretch to say that his shooting isn't sustainable. He's shooting 3's within a percentage point of his rate for all of last year, and at the same rate as his sophomore year. His free throw rate percentage for the month is below his season and career averages. The only number that really jumps out is his 2-point percentage. I don't know if he's making more jumpers (less sustainable) or just taking closer shots (maybe sustainable). Bradley is playing at his best right now, but he's not playing at a level so much higher than he's exhibited in the past that it would have to be seen as something that won't last. It might not, but he's performed at most of these numbers at various times in his career over longer stretches. They just generally haven't gone together.
It should also show the small increment between quakity NBA starter and rotstion player. It doesn't take much.