it's not that often that conditions are right for that to happen, but it sure can.
but i believe your right about the buckles & rings. i can't see a significant amount of water getting past them.
for those that don't use rings or buckles, speer hammocks sells a drip stopper that's really small & light.
and i liked what one guy did to hold a strip of fabric against the flat webbing.
he used a girl's hair clip.
don`t leave the CREATOR out of the creation!