“Instead, what happened was a very small piece of space junk hit the wire — and only the wire — at high speed, breaking it.”

We don’t know for sure if only the wire was hit. Perhaps other separate particles passed through the solar array. The solar array is designed to still function (provide power) with minor impacts and even some cracked solar cells. The power/voltage might be degraded somewhat.

Since the impact on the wire was near the base of the solar array, there is a chance (depending on the angle) the debris object(s) proceeded to the pressurized module(s) and truss structure below it. Fortunately, they have shielding.

But, it does raise an interesting question for the people that propose to pursue BEO operations by launching numerous small payloads and having them assembled on site autonomously (no human supervision provided for – in case of malfunction).