What is the definition of a condom used carelessly?

Any micro-tear: Since the concept of condoms is to act as a protective barrier, any use compromising efficacy, including microscopic tears, which allowed virus, bacteria or sperm to pass from wearer to recipient could be considered careless.

Improper Condom Use: Improper Condom Use includes applying condom after intercourse has begun, removing it too early, unrolling it prior to application, not checking for condom damage, use of expired condoms, re-using condoms, use of oil-based lubricant with latex condom or failure to withdraw penis in a prompt manner.