I'm not so sure. Look at their defensive shot maps from this year and last:
Last season they didn't allow much of anything from dangerous areas, just right around the league average and substantially below in the slot.
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This year they are still good in the slot, but are allowing many more shots around the dots and down low in somewhat dangerous areas. Note that xGA/60 is almost identical. It's the biggest shortcoming of the stat, it over weights the slot shots. Sure, they are more dangerous, but someone right at the dots or down low off to the side is pretty dangerous too.
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Those low shots are usually rebounds, so that means the goalies aren't absorbing pucks and the D isn't tying people up or clearing them. Probably why they are tied with SJ for the most high-danger goals allowed while being top-10 in preventing them. It's not bad luck, it's breakdowns down low.