Aluminum Pipe/Tube on Hardtop burst ?

[abl1111]

Weird. My brother just uncovered his 2005, 24' walk around Robalo with a hardtop. It was shrink-wrapped over the winter. The boat is MINT.

On a very top-ward portion of his hardtop, an angled but mostly vertical pc of approx 1.25-1.5" anodized aluminum pipe has a small 1" outward burst-looking crack ?

It seems way to high for any frozen water to make this crack ?! The path of least resistance would not really let ice/water go in this direction of pipe. But as we all know, water is funny stuff - ice probably weirder !

Any idea how a crack like this can happen ?

NOTE: When he first bought the boat, 3 years ago, there was a similar crack way down low near a mounting flange - we thought nothing of it - had it welded...

But now, our minds are churning for ... why ?