Say you write a story about an employee of Best Buy who accidentally kills his girlfriend by pushing her off a cliff whilst the two of them are dancing about like idiots stoned out of their gourd.
Would you really expect Best Buy to sue you because you painted a picture of a Best Buy employee getting stoned and committing manslaughter?
The disclaimer is more than adequate in these cases as far as the organisation is concerned.
In fact the disclaimer exists for the following reason:
Imagine that your fictive BB employee was called John Larsen. Now imagine that a real Best Buy employee called John Larsen picks up your story and reads about himself getting stoned and accidentally killing his girlfriend. John's been married fifteen years has two kids and is a member of the temperance society. So that people don't confuse real John with fictive John you put the disclaimer in. The organisation has nothing to do with anything, it's individuals who could conceivably suffer a tarnish on their reputation because of unfortunate coincidence that the disclaimer exists.
DISCLAIMER: Both John Larsens in my example are entirely fictitious I have never been in a branch of Best Buy let alone met any employees of said company whose name was John Larsen. Best Buy, on the other hand, really exists to the best of my knowledge.