I thought I'd follow the closing sentence of my last reply "...Because, yes, it may be due to the ISP as I said, but we recognize that it can be caused by our side. My experience here so far shows mostly otherwise though." with an explanation of the two scenarios that can lead to you seeing a different result at the end of your match.

Scenario 1
When it's caused by our own servers.
When a server is experiencing technical difficulties of such caliber that the technicians are required to restart it completely in order to implement the fixes they devised, all the simulations (Matches / Fixtures) that have to be ran while the restart is happening, will be done automatically and internally on the affected servers right after the reboot is complete.
In some cases a roll-back might be required (This happens extremely rarely), say an hour in time, all the matches that have been played after the point of return will have to be resimulated. Unfortunately in such cases the results may differ, and some times by a large margin.

Scenario 2
When its caused by data transfer between Client and Server - I already explained that this can usually be caused by factors along the whole line. Factors such as ISPs.
Matches are not simulated as one whole. They are done in parts. This way the manager has time between match-events (When the 2D animation fires up) to assess the situation and decide on his/her "next move" strategy wise.
The server sends info about what's going on to your game client (a goal, a yellow card, a chance missed, a corner, an injury, etc.), while your game client updates you of the situation as data is sent to it.
It can happen so that your connection to the game server loses consistency for a second or so, you may not lose connection but your client could miss some of the aforementioned events and you client would never "know" about this.

Example.
You're the Away Team.
The server sends the following events: Home Team goal > Corner > Yellow card for Away Team > Home Team goal > Away Team goal.
This means a 2:1 loss for you.
If your client missed out the 2nd Home Team goal then the result you would see at the end of the match would be a 1:1 draw. But leave the match and check out the match report / Fixture and you'll see the actual result.
Btw, everything that happened after the 2nd goal is absolutely real as well. You continued to observe and play your match with only the event about the 2nd goal taking a hit while being transmitted to your device and you never got the update of the situation.

The usual culprit behind this issue is, more often than not, Scenario 2. But as I said, we can't always know which one it is. So the best course of action is to immediately write to support. :/