This is invalid. If the scripter doesn't care whether there could be decimals, then it follows that they don't care how many decimal places there are. You can't really have it both ways.

Consider the most obvious example, a !calc script, where mIRC just spits out the result of $calc() to a channel:

Code:
on *:TEXT:!calc *:#:msg # Result is: $calc($2-)


If the idea is that a number could be an integer (!calc 16/4) or a double (!calc 16/7), the scripter shouldn't care about the precision. If they did care about precision, they would have $round() to limit it.

The "worst case scenario" is that the scripter does care about precision, but wanted at most 6 decimal places, and then assumed that since $calc() currently ever only showed 6, there was no reason to use $round(). This is probably the case you are arguing, but the script still functions, it just looks different. The result is still technically correct, even if aesthetically less pleasing. This would be unlike your scid example, where a similar assumption could outright change the correctness of a script (e.g. cause you to kick the wrong person, go into an infinite loop, etc).