Yesterday I went in with a group of four peeps and started on the first battle (I'm a myth).
During the battle I died, and when I fled Ervin had a tower shield on him.
When I returned it still showed that Ervin had the tower shield on him, so I cast pierce, but it did not do anything. I mentioned this, and someone else in the group said "because he doesn't have any shields on him." He said there was none on his screen, while on mine there was. I cast a shatter next round, and same result. The tower was still there.
So I cast Medusa on Ervin, and the shield fired off and it did like 290 damage. The other person said, "Gee, not very strong damage there."
On another occasion, I had fled and come back only to see that Taurus was showing no traps, even though attacks were setting off the "invisible" traps on him.
About the traps it's just that your computer has not fully loaded every thing that's happened since you fled and needs a turn or 2 to load it all up. That part is not a glitch