Um, no. You were underground at the end of the round; to the best of my knowledge, you cannot switch out. Furthermore, the EC for staying underground was handled incorrectly; I'm looking that up as we speak.
Aight, found it. According to the OP of the most recent SotG, it costs 6 EN to stay underground, and consecutive EN cost is applied. Furthermore, SDS has given to no-go to switching out (backed by every other user who responded on IRC), so yeah, that's not going to happen either.