If you goof up fluid flow, whether liquid or gaseous, things can get hot and be damaged. Things like the coolant systems of computers and motors and generators that could provide power and control signals to the centrifuges.
The centrifuges themselves just shutoff and slow down if there's trouble. However all of the highly specialized, ain't gonna be on Ebay, support machinery can get damaged and be very hard to replace or repair. Especially in Iran where all nuke-related machinery is embargoed from the only known suppliers.
It ultimately matters little in the big scheme whether the centrifuges themselves were damaged, or damage occurred to supporting electronic controllers and/or HVAC equipment, if enrichment was interrupted. It is like asking whether the Abrams Tank broke down because of a gas turbine problem or a broken track cog. Useful to the M1A1 engineers post-mortem, but either way, it missed the battle.
You are so aggressively pushing the “centrifuges are immortal” line I am wondering about your motivation. Is it just technical one-upsmanship or something else? For the typical readers, your presentation is going to cow them into believing Stuxnet had no effectiveness at all. Even Ahmadinejad has admitted that it did. His motivations tend to be different from those of “Israeli PR”.
Thank you for your replies,
You cleared up a lot of questions for me.
Merry Chrismas to you and your families.