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.
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.
I'd also have to somehow stop the person who found the block from knowing they found it on their miner

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% ...
Wasn't accusing you specifically, was just commenting on another reason a pool might see horrible luck. I'd venture to guess many miners don't check every piece of hardware for block found counts, and a bmminer restart or hardware reboot will wipe those stats.
It was easier to get away with back when the found block notification would scroll off the screen when you weren't looking.