User blog comment:Lia Schiffer/435: Panic at the Dollhouse/@comment-44061-20110203012153/@comment-1454424-20110203092722

There is a small setup for Ichigo's mother having been attacked twice. Chapter 188, page 9, Isshin says his only regret is that he couldn't same Masaki that night 20 years ago. Masaki didn't die 20 years ago (Ichigo who was 16 at the time wouldn't have been born otherwise) or at night for that matter. Masaki died 6 years ago during a rainy day.

As far as I recall, that line was the same in the anime. So we can be reasonably sure that it wasn't a mistake in the chapter that Kubo subsequently corrected in the volume. Which would imply that Masaki did indeed get attacked twice and it was the first time that was related to Ichigo's Fullbring ability - which were masked previously by his Shinigami powers, and the loss of Isshin's power. But we can't be sure so we'll have to wait and see.