Damage is about a complete electrical path. Some things are
in that path created by lightning and might be damaged Others
are not.

Why a single point ground? Learn why cows, for example, are
killed by a tree strike. Lightning did not hit the cow. Why
did the cow die? Because electricity also flowed through the
cow. Shortest electrical path was from cloud, to tree, into
earth, up cow's hind leg, down cow's fore leg, then on to
earthborne charges located maybe miles away.

So what in your house would have been in that same
electrical path? Apparently the AC controller was in a
destructive path. Maybe incoming up from earth - then
outgoing via breaker box earth ground. Other electronics were
not in a complete circuit - therefore not damaged.

How do we protect a cow? Surround a cow with a buried earth
ground - a halo ground. Cow is standing on equipotential
earth. How to protect your AC controller? Same. Another
example of why we demand single point ground. Is your case, a
halo ground - part of the single point earthing system -
would make earth beneath that AC controller equipotential.

BTW, if we built homes to protect transistors, then Ufer
grounds would be standard. Unfortunately, protection is still
an after thought - which is why APC sells protectors at tens
of times more money per protected appliance.

This also explains why buildings with utilities connected to
different earth grounds may suffer damage.

There is no magic force that caused damage. Smoke detectors
and GFCIs - not on APC protectors - also were not damaged.
What protected them? Same thing that protected other
electronics. APC hopes you never learn this.

Your question only listed selective examples. Good science
includes the entire list of damaged and undamaged
transistors. That APC solution provided no effective
protection. Why? Electronics already have effective internal
protection. Protection that may be overwhelmed without a
'building wide' protection system involving 'whole house'
protector and the most critical protection component - single
point earth ground.

This concept is was explained in that other discussion. APC
did what they could so that you never learn about earthing.

Ignoramus10397 wrote:
Very interesting, I am reading it.

I must note: when a lightning hit the tree next to our house, all out
computers and all electronics were on UPSes. None was hurt. The board
in the AC controller, though, did get fried.