That doesn't seem to be the case. Here's an article about the time-management used yesterday:
Thanks to NFL rules that re-start the game clock after a penalty, the Titans, while leading in the fourth quarter, took a delay of game penalty to take 40 seconds off the clock before punting, then false started with one second remaining on the play clock to take another 39 seconds off the clock. After that the Patriots helped the Titans by jumping offside, which allowed the Titans to run even more time off the clock. By the time the Titans finally punted, the clock had gone from 6:35 when the Titans initially faced fourth down to 4:50 when the ball was actually punted.
...
There are limits to how teams can exploit this loophole: With five minutes or less remaining in the fourth quarter, it doesn’t work because penalties always stop the clock inside five minutes. And if the Titans had done it a third time, they could have been flagged for unsportsmanlike conduct, which would have cost them 15 yards of field position and stop the clock. But until the rules change, it’s undeniably a successful strategy, one that Belichick has now both used successfully and had used against him.
Edit:
Also, apparently, they don't have to be consecutive delay of game penalties. That unsportsmanlike conduct is triggered if two delay of game penalties are triggered on the same down, regardless of any other penalty in between.