Look what i'm talking that its extremely unprofessional to "block" your services when the price of btc is not on your side.
If we follow your logic, i should go to bank when $1 is 1.775 BGN (my national currency) and they should tell me "Excuse me mr. Genov we can't allow you to withdraw your funds from your account right now, because exchange rate is too high for us". Do you want to convince me that its something normal. What if i had $10k in my e-coin.io, do you think that financial lost of $2k is something normal and i should say "oh ok, their system doesn't work again, i'm screwed". Obviously we're talking here about exchange rates financial scam, my lawyer has enough experience with such "exchange rate" scam tricks. If i was aware that their system didn't work at that time, i would go and exchange on local-bitcoins or some local dealer.
Here is the thing: was the NOT AVAILABLE deliberate or an overload of the system? I saw every thing from Blockchain to many other services momentarily time out when the price surged.. it happens, as most system see the SURGE of traffic as a DNS like thing. As you point out here that delay can cost you money, but it is also atypical of peek prices as every one that never logs in tries to to SELL, and over loads the system.