Thanks for your patience and apologies for my colleague jumping in and out of the conversation, I appreciate it's confusing when they said they couldn't help you!
If the case goes before a judge, and they have all of the evidence to look over, they will make a decision on the "balance of probabilities" which means they decide which version of the facts they think is more likely to be true. It's not like a criminal case, when they have to decide beyond all reasonable doubt.
But, even if the judge decides they think your partner did cause the marks, that's not to say you would not have contact - in many cases even with findings against someone they go on to have good contact - it's about whether there is any ongoing risk to the children and if there is a risk, how this can be managed.
So it's not going to be the case that if this goes against you/ your partner (and to be clear the allegations are very minor anyway), that you would not still have a fair amount of contact.
I hope this reassures you.
Do let me know if I can clarify anything,