Hi Dennis,
Uneven ground + gravel + my lack of care = much swearing. BTDT got the T shirt. So easy to happen on any big bike.
In answer to the question from Reddragon it is a yes and no answer because yes a top box can affect handling especially in side winds because of the wind loading which is almost behind the rear wheel exerts leverage and if one puts too much weight up there it is like carrying a stout passenger.
But most of the time one is unaware of it being there. I guess if one is passing a big lorry or coach or like in the fantastic description from TWB of passing a road train then with a big top box, extra care is needed due to the air blast and turbulence.
Regards,
K-BIKE