Given your indications of rolling left then right they may have hit wake from a preceding heavy jet...not uncommon these days where the aim is to cram as many movements/hr into airports. It can be nasty even in a 767 when you hit preceeding wake...often it is a LOT closer to the ground to...each time it has happened to me it has been < 200' at places like Dubai and Heathrow.
On twin jets, especially more modern widebodies, the pitch up is often in the order of 15-20 degrees at lighter weights. This is because the twins with both running are fairly overpowered (no such thing really
) compared to the 4 engined aircraft...to meet SE takeoff obstacle clearance/SE cruise driftdown and ETOPs requirements. The ETOPs part being to maintain high TAS (400ktas SE in the 767 case) to maximise distance allowed from suitable enroute alternates under 120 or 180 minutes ETOPs approvals where distance is the limiting factor not the actual time spent getting there.