AM operates at 30 TH/s for 11 months. AM then operates at 1,000 TH/s for 1 month. AM's lifetime average is then 1330/12 = 110.8. Now for investing purposes, should you treat AM as a 110.8 TH/s or a 1,000 TH/s operation? I hope you can see that you should view AM as a 1,000 TH/s operation. Hope this example helps clear up your misunderstandings.

Well it depends. In your example it operated for 1,000 TH/s for a month and that would be reflect in the slope of the lifetime average.
Day 330 - LTA 30.0 TH/s
Day 331 - LTA 32.9 TH/s
Day 332 - LTA 35.8 TH/s
...
Day 339 - LTA 55.7 TH/s
...
Day 360 - LTA 110.8 TH/s
On the other hand if it operated at 1,000 TH/s for a few hours and then fall back towards 300 TH/s over the course of weeks and then despite recovering from the low it showed difficulty breaking even 500 TH/s. If that was combined with a lack of information from the operator then no
I wouldn't consider it a risk free assumption that 1,000 TH/s can be maintained. Before I get accused of FUD I don't think this is likely however it certainly is possible in the sharp decline and lackluster recovery some equipment was damaged and without more hardware the network will NEVER reach its prior peak.
Didn't you see friedcat's post about exponential new equipment being manufactured in September and October?