Автовладелец сфотографировал препятствие на случай, если правонарушитель откажется признать ошибку.

Because сфотографировать is a perfective verb, and it presents the action as completed: the car owner took a photo.

By contrast, фотографировать is imperfective and would suggest a process, repetition, or an uncompleted action, such as was photographing or used to photograph.

So here:

• Автовладелец сфотографировал препятствие = The car owner took a photo of the obstacle
• Автовладелец фотографировал препятствие would sound more like was photographing the obstacle or photographed it repeatedly

Автовладелец means car owner or vehicle owner. It is a compact, common noun formed from:

• авто- = auto, car
• владелец = owner

Russian often uses this kind of compound noun where English might use a phrase.

So both are possible:

• автовладелец = car owner
• владелец автомобиля = owner of a car / the car owner

The first is just more concise and sounds natural in formal or official-style wording.

Препятствие is the direct object of сфотографировал, so it is in the accusative case.

However, препятствие is a neuter inanimate noun, and for this type of noun the accusative singular looks exactly the same as the nominative singular:

• nominative: препятствие
• accusative: препятствие

So the form does not visibly change, even though its grammatical role does.

На случай, если means in case.

This is a very common Russian structure:

• на случай = for the case / in case
• если = if

Together they mean something like as a precaution in case ... happens.

So:

• если правонарушитель откажется... = if the offender refuses...
• на случай, если правонарушитель откажется... = in case the offender refuses...

The full phrase emphasizes preparation for a possible situation, not just a neutral condition.

This is a very important difference between Russian and English.

In Russian, after если referring to a future situation, you normally use the future tense:

• если он откажется = if he refuses
• literally: if he will-refuse

Russian does not avoid the future here the way English does.

So this is normal Russian grammar, not a special stylistic choice.

Откажется is the future form of the perfective verb отказаться. Here it refers to a single completed act of refusal: the offender may refuse to admit the mistake.

Perfective is natural because the sentence is talking about a specific possible event, not an ongoing process.

Compare:

• если правонарушитель откажется признать ошибку = if the offender refuses to admit the mistake
• если правонарушитель будет отказываться признавать ошибку = if the offender keeps refusing / is going to be refusing to admit the mistake

The second version would suggest a more prolonged or repeated refusal.

Because признать is the perfective infinitive, and it means to admit / acknowledge as a completed act.

After отказаться (to refuse), Russian often uses a perfective infinitive when referring to a single action someone refuses to do:

• отказаться признать ошибку = to refuse to admit the mistake

If you said отказаться признавать ошибку, that would suggest refusing to do it in a more ongoing or repeated sense, like refusing to acknowledge the mistake over time.

So признать fits better here.

Because it is the direct object of признать:

• признать что? → ошибку

The dictionary form is ошибка. In the accusative singular, it becomes ошибку.

So:

• nominative: ошибка
• accusative: ошибку

This is a standard feminine noun pattern.

The subject is правонарушитель.

That noun is in the nominative case, and it is the person performing the action of refusing:

• правонарушитель откажется = the offender will refuse

Then признать ошибку is the infinitive phrase that tells us what the offender may refuse to do.

Not exactly.

Правонарушитель means offender, violator, or person who has committed an offense. It is a more formal and legal-sounding word.

It comes from:

• право = law/right
• нарушить / нарушение = to violate / violation

By contrast, преступник means criminal, which usually sounds stronger and is more clearly connected with a crime.

So правонарушитель can be appropriate for a broader range of legal violations, including less serious ones.

Yes, the sentence could be rearranged, because Russian word order is fairly flexible. The current version is natural and neutral:

• Автовладелец сфотографировал препятствие на случай, если правонарушитель откажется признать ошибку.

This presents the main action first, then the purpose/precaution.

Other orders are possible, for example:

• На случай, если правонарушитель откажется признать ошибку, автовладелец сфотографировал препятствие.

That version brings the precautionary reason to the front for emphasis.

So the meaning stays basically the same, but the focus changes slightly.

Yes. Препятствие literally means obstacle or hindrance, and it can be either:

• physical: something blocking the way
• abstract: something that makes a process difficult

In this sentence, it most naturally refers to a physical obstruction, especially since it was photographed as evidence.