It's a great pool, that's why it's always has a ton of the network I'm not sure why you say it's well above 51%, talking about forking or  double spend attacks is not relevant for scrypt. We have  ~4GH/s on hash.so, so "we" have >51% of flap for quite some time.

The only valid concern is DDoS attacks, and flap network loosing tons of hashing power but with KGW even it is not an issue, coin would retarget itself quickly.

More info in here: http://www.reddit.com/r/flappycoin/comments/1yihen/seems_this_pool_httpsflaphashsoindexphp_is/cfkvxhp

I guess I need to write this up somewhere, because it keeps happening quite often, I can't complain tho, it means that my pools are great