I've never seen anything like this. I've always had the points add up to what they should.
It'd be much easier to figure this out if you posted some screenshots of what's happening.
First, a couple of stupid questions.
1. You turned off CPU assisted recruiting, right? If not, maybe you're not really spending 700/week on them as the CPU is changing it. This would be really obvious, though as you'd see the CPU's # of weekly points on him when you advanced instead of the 700 you thought you were spending.
2. You've offered them a scholarship, right? This would be the best explanation I can think of. If you haven't offered, then the max you can get to is 73% locked. At that point, you could add 1 billions points of recruiting during the week and you won't go up at all. If this happens, then everyone else on his list gets a free 20ish points per week and then they get their bonus + their weekly points per week. See the attached photo of Anthony Cooper as an example. Ohio hasn't offered a scholly so they're maxed out @ 73%. Everyone else gets a free 20 points (this is obvious by looking @ Nebraska, Alabama, LSU, and Georgia who don't have him on their boards @ all, but are gaining 20 points on Ohio). Plus look @ Michigan (me) who gained 970 points (20+350+600 = 970). It's obvious that Notre Dame is spending 500 points per week on him (20+290+500 = 810).
Based on your 2nd post it sounds to me like you didn't offer him and in the 1st post you were close to 73% but still under it so some of you 700 points counted (enough to get you to 73%) but not all. This caused them to gain some points on you. Then in your 2nd post you were already at the 73% threshold so you got NONE of you 700 NOR your bonus points and that's why they gained a TON on you that week.
Also, here are just a couple of corrections for you.
1. You don't get +50 points when offering a scholarship. The only tangible effect of offering is that it allows you to pass the 73% locked threshold and eventually sign the recruit. For proof, see the before/after photos of Dennis Vandermeulen. The 1st one shows I he had no offer and I spent 600 points the previous week. I gained 930 points on everyone (600+330 = 930). I then offered him a scholarship and then advanced and in the next week, I still gained 930 points, despite me offering a scholly the previous week and advancing instead of the 980 points you would've predicted with the offer.
2. You actually get double your visit points for visits, not just the amount shown. This one gets pretty fuzzy because there is some max cap somewhere that I haven't figured out. This means that sometimes you can't see double the points because you hit the cap and it won't give you more. However, when you don't hit the cap it's very obvious. Look at the pictures of Tim Cameron. He visited last week and had a 550 pt visit. I spent 200 points on him and he had a 410 point bonus. You can see that I gained 1710 points on everyone from the visit. This is (200 + 410 + 550
*2 = 1710).