Issue at church today with another child with ASD

I teach the 2-3 year olds once a month. Our church is very small and probably half of our attendance are children. I am used to children with ASD since we have a few in my family and I have several friends with kids on the spectrum. There is a 6 yo boy with what I would describe as seemingly like Kanner's autism that is put into the 2-3 class. He can be super sweet sometimes but other times hard to handle (I know, this is typical).  He really doesn't have any words, no eye contact at all, he stims a lot by banging items against his teeth (carries a popsicle stick around to do this most time or picks up other items), he is toe-walker. He mostly keeps to himself but sometimes steals stuff from the 2 & 3 year olds and throws it, and he is a runner.

Herein lies the problem. Some days are fine but if he's having an off day, he tries whatever he can to escape and run out of the room.  His mom brings him in after the music part of church so she can hear the sermon. DH said he was upset already during the music portion today. Anyway, our pre-school age rooms are joined together by doors. So this room I'm in has a door on the left that leads to the 4-5 yo room and a door to the right that leads to the infant room and a baby gate in the front doorway to the lobby. The side doors to the other classrooms do not even have the metal things in the doors so they don't really latch. They open with a simple push or pull plus he also knows how to undo the baby gate. So I'm expected to teach a set lesson I am given which also involves art type activities, story time, ect. In which I have to assist the kids while sitting at a table. He does not sit, ever at church so it is during this time that he typically tries to make his escape. His favorite place to run to is the infant room. Well today he escaped/tried to escape multiple times. I quickly went in and carried him out the first time (but that left the other kids alone which I don't like doing) and that upset him more (he likes being held sometimes and sometimes he doesn't). The second time, one of the ladies in the infant room said he could stay in there (actually went through school for ABA but is working with animals instead of humans) but I could see that the other lady (a first time mom with a 6 week old) was extremely uncomfortable with him being in there. So I stood in the door way, trying to coax him back with various toys from the infant room because he likes those better. Thinking, getting him back on his own will might be better. He touched the swing her baby was in and she snatched her baby up and left the other teacher alone in the infant room. She then stared through the glass window of the infant room until I eventually got him coaxed back into my room and he seemed content for about 15 mins so then I began another activity and he dashed for that door again. I caught the door this time and he immediately ran to the other door and I managed to get that one as well but this time he scratched my neck which I didn't realized until DH pointed it out to me when church got out. I knew he grabbed at my shirt but I guess I didn't feel the scratch but it was large about 5 inches down my neck

About that time, the school age children came in from our other building and quite a few of them stood at the baby gate looking in at the classroom.  Of course, this upset him and I asked them to back away from the gate. Then he wanted out of the gate to get his mom. Church released and DH walked up and could see that he was in meltdown mode and he went to get his mom. In the meantime, he tried escaping out the 4-5 yo room door again but luckily, his mom was coming in that way to get him about the same time. She said to me, Oh, you could have come and got me and DH answered for me and said that I was alone in the room and obviously can't leave a bunch of 2-3 yo kids alone to come and get her.

So our church is short "staffed" on volunteers for the kids and we have a lot of kids. I asked DH to please come in with me from now on. I can teach and he can be on door watch. He used to teach school age while when I was in the infant room but he decided not to teach anymore and the moved me up (without asking) to the 2-3 room when DS moved up so they wouldn't have any issues with him helping me.The problem is how to approach the situation with our pastor and his wife (who is head of the children's ministry and a daycare director). I mean, I will have "fixed" the situation for myself but there are 2 other weeks I'm concerned about. They just rearranged some volunteers and schedules this month. His mom teaches one of the weeks so there isn't any fleeing going on with her there for the most part. There is another volunteer who has no children at all, very young who formerly volunteered in a partner set in the infant room and the other week is taught by a first time mom to a 6 month old who just started volunteering. So neither of them have any experience with him or this age group. I'm a little concerned for others to be in this situation on one of his off days.

I think having a second person in the room would be best because also these 2-3s are sometimes potty training and the bathroom is down the hall, but I don't think that's plausible with a church this size. I think if there were a way to secure the two side doors during class time, that it might help tremendously. I just don't know how to suggest these things without it seemingly like I am complaining about the boy because like I said, he is really sweet most day and really only hard to handle on his "off" days.

His mom is very sweet but doesn't like to discuss pretty much anything, regarding him. I have no idea what his behaviors are outside of what I have seen personally or what kind of therapy he gets. She does know my DD is on the spectrum and I've tried to spark conversation with her about it and got nowhere. Any suggestions on things I might be able to do or mention to the church to help the safety situation of all the kids? When he flees, attention has to go completely on him and getting him back into the room and we all know it takes about 2 seconds for something bad to happen to another kid. I have never dealt with a runner before.