I don't believe I THOROUGHLY understand the "default-information originate [always]" commands in OSPF, so I set something up in my lab wherein Router E ran OSPF and had the "default-information originate" command configured. Routers F,G, and H became neighbors, but things went wacko during the adjacency-formation process (a router with a lower ID became DR, one neighbor stayed in EXSTART for five minutes...it was MADNESS). So I powered down E, F, and G but left H on.
I noticed an hour later that despite Router E, the originator of the default route, being down for more than an hour, Router H still had the "candidate default" route in its table, with E's interface as the next hop.
As best I know, dynamic routing info would not stay in the route table of a neighbor router running a protocol if that route's next-hop router went dead.
So with advertised default routes, they are originated by a routing protocol on one router but then considered static by the routers that receive it?
(Also weirdly, I did clear ip route * on Router H and the default route disappeared but then reappeared anyway; despite Router E remaining completely unconnected.)