Sorry to hear things didn't turn out as planned and that Mosey is so sore. Good idea to put padded boots on him as long as he's uncomfortable. The general ideas on the link are sound but how they are implemented can be problematic.
There could be a number of factors involved here but without pictures of the trim there's no way to make any specific comments. Some things to consider would be: was any sole and/or frog removed? were the bars heavily trimmed? were the heels lowered? Is he sore on all four feet or only some?
It's possible he had trapped collections inside that the trim is mobilizing = abscesses. These can more debilitating/painful than laminitis. His body may be needing to adapt to the new configuration of his feet, which can make the body sore as it uses itself in ways it hasn't done in a long time.
Jan 2005, RI