body fat calculation - calipers question

Just had my body fat % calculated by my gf's personal trainer (a multi-titled masters bodybuilding champ who is cut and muscled like you wouldn't believe). He's been a trainer and pro body builder for 40 years, so frankly I figure he knows how to measure body fat because it's so crucial in that sport.

He tells me I'm 35.4% body fat, but that my lean mass is 118.9 lbs. I weigh 154.

For comparison, in February I was 168lbs with 123lbs lean mass, or 27% body fat. I had it measured by 2 different people over 2 weeks that month and that was the average between their measurements. One of the measurements was at a hospital health center, so again, I know calipers are subjective but it's not gonna be THAT far off.

I assumed body fat % was :
lean weight as determined via some mystical formula for caliper measurements / total weight

This guy did total-of-caliper-measurements (202 in my case) divided by my current weight, multiplied by .27 to determine percentage of body fat. Which is 35.4.

Can anybody educate me on this? I am so baffled. He was flying thru it and it may have just done something incorrectly. To me, my lean mass (and again, I am unclear how he came up with the number 118.9) divided by current weight gives me about 22.7% fat.

What gives, does anybody know? I really want to use my lean mass to help me figure out my ultimate target weight, which isn't going to be 125lbs like all those stupid charts say for my height. So I would like to know how to project out assuming the same lean mass, and if I'm differeing by over 10% from his measurements I don't know that I can trust my numbers.

Thanks