if they toss back to back that is 1 in 10000 chance my guess is the pool has
bad code
bad server
bad internet
or bad gear mining on it.
bad code
bad server
bad internet
or bad gear mining on it.
Or the pool owner decided to snag a block reward for themselves. I hazily recall a pool getting caught out for the statistical improbability of their never finding extremely lucky blocks back around 2012. Turned out the owners were taking all the blocks the pool found below a certain share threshold.
Now that would be a tricky thing to do unless Bitmain put something into their bmminer to hide blocks ... ... ... ... ...
Low % blocks ... 3 in the last 100 are: 1.774% 1.175% 1.141% ...