Taillight removal for water leak 2017 320S

We recently found evidence of water intrusion inside the rear starboard (grass) side corner  Seeing other posts regarding this issue I decided to pull the taillight assembly off this side for an initial look. 
There are four larger screws on the assembly panel, five smaller ones on the adjoining side panel, and four under/around the grab bar which appear to hold the two trim pieces together. I removed all of these. At this point the rear trim/light assembly will wiggle around but not pull free. It appears "stuck" to the trailer body directly under the reflector. 
Question: Is the reflector assembly hiding another fastener, or is this a result of a big blob of silicone adhering the back of the assembly to the trailer body?  If it's the latter, I can slide a plastic putty knife in there to break the pieces free from one another, but there's not enough of a gap for me to see in there. The last thing I want to do is break a piece of teal trim "fixing" what is likely a simple issue. 
Also, please let me know if this picture is not re-sized correctly. I downloaded an image re-sizer and "think" it's right. Note the quote marks around "think". 
Thanks in advance for advice and comments! 
Fred