[Red Lion]

Were you able to confirm the SQL injection ?
Because i only get an error message if i submit anything but numbers and whitespaces.

[Red Lion]

Can you post a query where you didn't get an error ?
Don't think that this is exploitable, as you don't get anywhere only with numbers.

[Red Lion]

As i said, when ID contains something else but numbers, you'll get the error.
id=36s --> error
means if it was vulnerable the SQL query would have to look like
where id=36s
but the error is

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 2

The conclusion is id is casted to int before it is inserted into the SQL query.
If id contains a string the cast fails and id is empty.

You get the same error if you submit id=''

Sorry but this parameter is not vulnerable to SQL injection.

[hahdbwoannniabs]

It's probably something they put there purposely as a honeypot or to ward off hackers.

[Th3PonyWizard]

It's probably something they put there purposely as a honeypot or to ward off hackers.

I feel this is more of a lazy workaround rather than an actual attempt of something, such as forced casting. Like the dude above said, anything not integer is error.
SELECT * FROM `table` where `id` = {(int)$_GET['ID']};
or something.

Leave it ... theres no /login or /admin !

Yeah, who needs database records when there's no clear privileged URL detected! Boo!