If your buddy's garage is anything like mine, the temperature swings in it can cause condensation and corrosion on metal parts. Looks like a combination of that and [censored] plating on the steel parts of that aluminum jack.
I wanted a second floor jack and just picked up the steel HFT 3 ton low profile, rapid pump jack today. It was on sale for $84.99. I had intended to buy the regular (non-low profile) 3-ton with a coupon for $79.99, but liked the looks and height range of this one better for $5 more.