re condoms:
What if, yes, the dropped condom wrapper in location of Trish's rape belonged to SleazyJim, but was from his unsuccessful attempt at "sex up against the tree" with waitress, slightly earlier on party evening?
Waitress stated it was consensual until he got too rough. Someone like SleazyJim wouldn't be used to rejection, as he's clearly delusional that he's God's Gift to all women, so probably slunk off elsewhere, pride battered, to remove/ dispose of actual condom itself.
It might seem too coincidental that in same location as Trish's later rape (unconnected to Jim,and perpetrated by somebody else/ somebodies else), but for all we know, it could be a well-known spot to any locals involved with the sub-plot of dubious porn filming/ dogging/ er..."night fishing". Maybe they've already got covert cameras/ lighting rigged up?
And forensics would've sussed his fingerprints on wrapper, I suppose. (Unless he's into bdsm kinky gloves?) 
Still puzzled as to what makes SleazyJim's condom brand apparently so damn unique, though? Not as if they're niche HUGEbrand (a genuine make!), if from local pharmacy?
Graphista and Sapphire,
As PPs mentioned, well predicted re Leah! And being first to theorise about spyware!
Lila,
Have you complained to Aldi about your fajita trauma?? Dying to hear their response... 