That doesn't help much! What does "red team" mean as a verb in this case?

To do the work of a red team. To try to break something in order to identify its flaws.

It’s very common in English for nouns to become verbs that mean the thing you use the noun to do.

I don’t know if that’s historically common but I sometimes verb like this when I’m too lazy to think of phrases like “think of phrases”. (Here’s to hoping that makes any sense.)

English verbs nouns all the time

I don’t like it, but the usage is “[attack as a] red team”, in other words “act in an adversarial manner”.

In that context, the title still makes no sense.

You sometime see it as "red teaming" or "red team'ed" which might be more grammatically correct?

Regardless, "to red team something" really is a common saying in the security industry. It's the corpo/whitehat version of "to pwn".