Strange behavior from Core Data in iOS swift app

This is iOS 8.1 and Swift on Xcode (latest GA release) with identical behavior on both simulator and a device.

I have three entities: Match, Score and Team. Each Match has two teams, team1 and team2. Score also has team1 and team2. Match has a 1x1 relationship with Score, the fields being bet and betFor respectively. Match is identified by its field matchNumber.

So I have the following (psuedo)-code:

match.bet = score
score.team1 = match.team1
score.team2 = match.team2
context.save(&err)
// Check if err is nil or not
match = Match.lookup(context, matchNumber)
// Try doing something with match.bet.team1 and it crashes

Basically an attempt to retrieve the information I just set comes back as nil.

I have tried several things, including returnsObjectsAsFault = false during the fetch etc. When I open the .sqlite file using sqlite3, I can see the entries being made. I tried using sql debug flag set to 3, but nothing jumped out. I am not saying that avenue is exhausted, but I definitely am.

Any thoughts on what could be going on here? I am stuck on this for quite some time and any thoughts would be appreciated.