No need to be pedantic. No-one's arguing about the meaning of 'at your own risk', it's just that your decision to use this software affects more than just yourself.
I think the response you are replying to was a reaction to the possible interpretation that OpenPilot puts pedestrians etc. at increased risk, or that it put the driver at increased risk.
While a reasonable interpretation includes putting the driver at increased /legal/ risk relative to a system where the manufacturer represents it as for sale for autonomous driving, it is unreasonable to infer that this puts the driver at greater risk of being sued, having to sue, or monetary loss. OpenPilot may be better / safer than the competition such that using it lowers your risk of accident, monetary loss, etc. even including any purported loss of the ability to pass the buck to the manufacturer.
To be fair the person they're replying to was the one who was either being pedantic of trying to score some cheap virtue points by stating the obvious (and I'm giving them the benefit of the doubt and assuming the former)
