I have conceded 4 goals in 20 minuites withn 4/4 shots of the oppo 100% accuracy.
1 penalty/red card at 8min, 2FKs and one CK. (with defensive wall and aerila ability defenders)

Turn this around

What I am trying to say from above is that using one example cannot make a theory as there will be same numbers of counter examples.
I have as well turned around some matches like yours above.

But some times it is nothing you can do in-game.. it was not your day :P
This does not mean that match was fixed to destroy explicitly you,
Just the calculations were not on your side...

Also as we talk about calculations you can never exclude that some calculations are wrong. (wrong in terms of concluding having a realistic sim football manager game)
No software is bug free.