Did Chris mention when this was? Was he in elementary school, middle school, or high school? Regardless, his apparent lack of curiosity at the reason for the payment at the time is pretty interesting.
Reminds me of this quote from the video of the lego high school he uploaded:
"And there's my dad, negotiating with the Principal, because, that's one way to make friends in High School, negotiation"
Part of me wants to say that Chris doesn't understand this situation and that Bob was just hiring someone to keep Chris from running into traffic, getting kidnapped or lost (this is when he was in Richmond right?) since Bob was probably too old to do it himself. Especially since Chris mentions that she didn't really hang out with him except to walk him to and from the bus stop.
The other part of me says this is another sad situation and further proves Chris didn't have any kind of friends ever and the ones he did have were all fake and this might have extended all the way back to elementary school.