What does the flashing lightning icon over minions mean?
Solution 1:
Recently all of the status effects in League of Legends were standardized, specifically, Stuns, Fears, Blinds, Silences, and Taunts. What you are seeing is the Taunted debuff.
The way points work in Dominion, is that they taunt nearby enemy minions to attack them (and in the process, capture the point).