Why do you need a gutter on a flat roof?
And no if this is a question.
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PS this msg is NOT too short
Ah, no it is not.
And welcome to our forum, Jeffery!..Enjoy! 
Is this a commercial property or residential home?
If residential, is BUR common on homes in your area?
What area are you in?
How did you determine it is a BUR, and not a ballasted system?
Curious why the gutters also. Scammed by a salesman? Either way, they are useless as installed.
Ballasted with old, sharp, crunchy rocks. Floor drains are probably all clogged up with no overflow scuppers. Possibly fills up like a pool and overflows the sides so someone added a gutter, lol. I would not be surprised.
Need a wider angle picture, looks like that gutter install is pointless from the posted pic.
This was my very first home inspection 
. The home was built in 1957 and it does have a slope but maybe a 2/12. The buyer had already got a roof inspection before my inspection so I excluded it out of the report and only inspected it for learning experience. I am not that sharp with flat roofs or low slope. But it had a large even amount of pebble size gravel all over the roof so assumed a built up roof but I am new so probably wrong 
. I do have a few other pictures I will post that hope fully give a better angle or view.
You are correct about the BUR.
That roof edge flashing detail will direct water under the flashing before it spills into the gutter.
The gutter might be hung on the outer wall assembly but that top flashing is not installed properly. Fasteners penetrate the gravel stopper and BUR roof membrane, the plied stripping. That will cause a problem over time as water enters fastener openings. As well the fasteners are not evenly spaced, are corroded and not sealed with an approved caulking.
The back of the gutter pan goes behind the integrated gravel stopper / drip edge flashing. Just like on sloped roofing systems, the back of the gutter pan is fastened behind the drip edge flashing.
Just my 2 cents.
Non professional installation.
Refer for correction.