I apologize for the amateur thread but I am having a hard time diagnosing a sheet of film I just got back. I was out this weekend for a short few minutes wanting to make some type of photograph after being rained/snowed in. I exposed 3 other sheets and there were no issues like this, the lab I used was a local one I don't really go to all too often since it has had a reputation of messing up film (water spots, streaks, etc) but it was the closest and I just wanted to test out the new 150mm I got.

Could someone tell me if this is a light leak or if it is a problem that occurred during developing?

Thanks all,
Tony