Yes. I hang out on r bitcoinmarkets on and off and the Bitmex outage/rapeage is a well known occurrence. It could be selective scamming of their users but it's also easy to forget just how rapidly they've grown and how much load there must be now.
Neither am I unaware of the facts nor about the overloads that may happen when a lot of unexpected audience as well as activity levels spike in volumes that couldn't be handled by servers, but what about those unhealthy pumps that happened as a proof for the artificial climate which is created by Bitmex guys when those $500 and $800 pumps in a single shot within a single candle took place?
Bitfinex often behaved in a very similar manner on occasion of moments of intense action but they're just as ethically questionable. The old adage about only playing with what you can afford to lose applies a millionfold with shitholes like Bitmex.
I've seen volumes spiking immediately when such announcements about maintenance or anything else like bugs found or system issues came into existence over Bitmex, and can't forget to add one more thing here that even being verified, they close your account for no reason if you've got to tackle the odds and win something really big against them and it's literally possible in crypto world.