Looking at it, Getting mad and leaving do nothing to help solve what the actual problem could be. Check the sensor wire, power cables (especially for "plug in" type batteries with bullets on the battery itself), Sensor wire, ALL solder joints then check to see if ESC is in LiPo mode with a Nimh or has an uncharged LiPo in it.
If all that checks out fine remove it from the vehicle and bench test it, If it fails there grab a known good ESC, motor and battery and test each part individually. Also isn't Speed Passion actually rebranded Hobbywing? If so there could be led's on it that will signal problems.
It's good you guys are offering him a replacement at cost but most likely it is a simple fix or operator error that is the problem. If it doesn't smell burnt it's probably a minor fix.
Just my newbie 2 cents
P.S. - Jaypeezy: If it worked good for you and had no problems then you should not feel bad or refund anything really, There are a TON of factors that go into running and maintaining RC cars that can cause issues and since you were not there when it broke or helping him install the system you are not accountable at all.