That´s probably the first time I see 7 players on the opposite side of the pitch. There is an "unwritten" rule in T11; the amount of players on your side of the pitch should be "equal" to/on the opposite side of the pitch. One thing is to play a 3W/N defence line and then go with 5 + 2 players on the middle/attack (say 2 DMC, 3MC and 2ST or 5ML/MC/MR and 2ST: 7 players).
You could have been playing simple 4-4-2 and beat him easy.