I'm not an expert on contract law, but I'm fairly sure that one party modifying a contract without the other person's notice or consent does not make the modifications legally binding, which is why you do need to get the other party to initial changes you've made.
A contract is a physical expression legal agreement which both parties are supposed to know about, it's not a magical piece of paper which enforces whatever's written on it.
I should note that in this particular case the chances of any of this ever mattering are essentially zero. Just letting everyone know, in case they think they can go out, buy a house and move a decimal point in the sales contract while nobody's looking.
So if I don't know what's on the paper because no one has made sure that I do then I still can be upheld on what I signed but if the guy who gave me paper to sign doesn't know what's on the paper because he didn't notice my changes then he can't be liable?
You have a duty to read before you sign a contract. In this case, they can claim you tricked them into thinking you'd signed the form contract, and that they relied on that agreement when they provided you care. IANAL, but I suspect you will lose this unless you can show that the staffer accepted your changes knowingly.
I'm still not an expert on contract law, but I would suggest that yes, that's the case. The law isn't necessarily perfectly symmetric between the original text of the contract and handwritten alterations put in at the time of signing.
