This may be a dumb question but why on earth would anyone paint the inside of the calipers or even spray anywhere near the pistons or seals? I thought masking tape was made for a reason. It's not like you can actually see in there with x-ray vision through the rotor and brake pad to even need to worry about what it looks like

Paint holding in heat that contributed to the malfunction of a caliper??? Wow, it's not like it's an intercooler or block. I guess Porsche should recall every single one of their brake systems on all their cars in the last 30+ years because they are all painted either black or red.

Honestly, i'm willing to bet that mechanic bent you over without astroglide...i'm sure it just needed to be bleed or did you have brake fluid all over your wheels and rotors?